diff --git a/Dockerfile b/Dockerfile
index f23a48e31cb..08e0fc07d22 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -53,7 +53,6 @@ COPY ./addons/onedrive/requirements.txt /code/addons/onedrive/
 COPY ./addons/onedrivebusiness/requirements.txt /code/addons/onedrivebusiness/
 #COPY ./addons/osfstorage/requirements.txt ./addons/osfstorage/
 COPY ./addons/owncloud/requirements.txt ./addons/owncloud/
-COPY ./addons/s3/requirements.txt ./addons/s3/
 COPY ./addons/twofactor/requirements.txt ./addons/twofactor/
 #COPY ./addons/wiki/requirements.txt ./addons/wiki/
 COPY ./addons/zotero/requirements.txt ./addons/zotero/
diff --git a/addons/s3/README.md b/addons/s3/README.md
index 6b4261bd77a..d3347506daa 100644
--- a/addons/s3/README.md
+++ b/addons/s3/README.md
@@ -16,3 +16,23 @@ If you already have an access key and ID, skip this step
 2. Scroll down to Configure Add-ons
 3. Connect your account and enter your ID and secret
 4. Select a bucket to work from, or create a new one.
+
+
+## Creating a restricted-access AWS user for S3 connection
+
+1. Login to AWS
+2. Open Identity and Access Management
+3. Create a user, assign name, set "Access Type" to "Programmatic Access"
+4. Permissions (simple):
+   1. Add "AmazonS3FullAccess" policy
+5. Permissions (minimal):
+   1. Click "Create Policy" => opens a new window
+   2. Make a new policy with the following Actions enabled: `["s3:DeleteObject", "s3:GetObject", "s3:ListBucket", "s3:PutObject", "s3:ReplicateObject", "s3:RestoreObject", "s3:ListAllMyBuckets", "s3:GetBucketLocation", "s3:CreateBucket"]`
+   3. Resources: *I just do "All Resources", but an AWS-educated person would know better about how to narrow it down.
+   4. Click "Create"
+   5. Return to "Create User" window
+   6. Reload policy list
+   7. Search for your new policy and select.
+6. Tags: *eh*
+7. Click "Review", review, then click "Create user"
+8. Note "Access key ID" and "Secret access key".  These are the inputs to the OSF S3 addon.
\ No newline at end of file
diff --git a/addons/s3/apps.py b/addons/s3/apps.py
index 48943b4d87d..ef520daeed1 100644
--- a/addons/s3/apps.py
+++ b/addons/s3/apps.py
@@ -12,6 +12,7 @@
 
 class S3AddonAppConfig(BaseAddonAppConfig):
 
+    default = True
     name = 'addons.s3'
     label = 'addons_s3'
     full_name = 'Amazon S3'
diff --git a/addons/s3/models.py b/addons/s3/models.py
index b42a1552696..226467776bb 100644
--- a/addons/s3/models.py
+++ b/addons/s3/models.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 from addons.base.models import (BaseOAuthNodeSettings, BaseOAuthUserSettings,
                                 BaseStorageAddon)
 from django.db import models
@@ -8,11 +6,18 @@
 from addons.base import exceptions
 from addons.s3.provider import S3Provider
 from addons.s3.serializer import S3Serializer
-from addons.s3.settings import (BUCKET_LOCATIONS,
-                                        ENCRYPT_UPLOADS_DEFAULT)
-from addons.s3.utils import (bucket_exists,
-                                     get_bucket_location_or_error,
-                                     get_bucket_names)
+from addons.s3.settings import (
+    BUCKET_LOCATIONS,
+    ENCRYPT_UPLOADS_DEFAULT
+)
+from addons.s3.utils import (
+    bucket_exists,
+    get_bucket_location_or_error,
+    get_bucket_names,
+    get_bucket_prefixes
+)
+from website.util import api_v2_url
+
 
 class S3FileNode(BaseFileNode):
     _provider = 's3'
@@ -53,10 +58,12 @@ def folder_path(self):
 
     @property
     def display_name(self):
-        return u'{0}: {1}'.format(self.config.full_name, self.folder_id)
+        return f'{self.config.full_name}: {self.folder_id}'
 
     def set_folder(self, folder_id, auth):
-        if not bucket_exists(self.external_account.oauth_key, self.external_account.oauth_secret, folder_id):
+        bucket_name = folder_id.split(':')[0]
+
+        if not bucket_exists(self.external_account.oauth_key, self.external_account.oauth_secret, bucket_name):
             error_message = ('We are having trouble connecting to that bucket. '
                              'Try a different one.')
             raise exceptions.InvalidFolderError(error_message)
@@ -66,7 +73,7 @@ def set_folder(self, folder_id, auth):
         bucket_location = get_bucket_location_or_error(
             self.external_account.oauth_key,
             self.external_account.oauth_secret,
-            folder_id
+            bucket_name
         )
         try:
             bucket_location = BUCKET_LOCATIONS[bucket_location]
@@ -75,32 +82,46 @@ def set_folder(self, folder_id, auth):
             # Default to the key. When hit, add mapping to settings
             pass
 
-        self.folder_name = '{} ({})'.format(folder_id, bucket_location)
+        self.folder_name = f'{folder_id} ({bucket_location})'
         self.save()
 
-        self.nodelogger.log(action='bucket_linked', extra={'bucket': str(folder_id)}, save=True)
+        self.nodelogger.log(action='bucket_linked', extra={'bucket': bucket_name, 'path': self.folder_id}, save=True)
 
-    def get_folders(self, **kwargs):
-        # This really gets only buckets, not subfolders,
-        # as that's all we want to be linkable on a node.
-        try:
+    def get_folders(self, path, folder_id):
+        """
+        Our S3 implementation allows for folder_id to be a bucket's root, or a subfolder in that bucket.
+        """
+        # This is the root, so list all buckets.
+        if not folder_id:
             buckets = get_bucket_names(self)
-        except Exception:
-            raise exceptions.InvalidAuthError()
 
-        return [
-            {
+            return [{
                 'addon': 's3',
                 'kind': 'folder',
-                'id': bucket,
+                'id': f'{bucket}:/',
                 'name': bucket,
-                'path': bucket,
+                'bucket_name': bucket,
+                'path': '/',
                 'urls': {
-                    'folders': ''
+                    'folders': api_v2_url(
+                        f'nodes/{self.owner._id}/addons/s3/folders/',
+                        params={
+                            'id': bucket,
+                            'bucket_name': bucket,
+                        }
+                    ),
                 }
-            }
-            for bucket in buckets
-        ]
+            } for bucket in buckets]
+        # This is for a directory for a specific bucket, folders (Prefixes), but not files (Keys) returned, because
+        # these we can only set folders as our base folder_id
+        else:
+            bucket_name, _, path = folder_id.partition(':/')
+            return get_bucket_prefixes(
+                self.external_account.oauth_key,
+                self.external_account.oauth_secret,
+                prefix=path,
+                bucket_name=bucket_name
+            )
 
     @property
     def complete(self):
@@ -124,7 +145,7 @@ def deauthorize(self, auth=None, log=True):
 
     def delete(self, save=True):
         self.deauthorize(log=False)
-        super(NodeSettings, self).delete(save=save)
+        super().delete(save=save)
 
     def serialize_waterbutler_credentials(self):
         if not self.has_auth:
@@ -135,10 +156,16 @@ def serialize_waterbutler_credentials(self):
         }
 
     def serialize_waterbutler_settings(self):
+        """
+        We use the folder id to hold the bucket location
+        """
         if not self.folder_id:
             raise exceptions.AddonError('Cannot serialize settings for S3 addon')
+
+        bucket_name = self.folder_id.split(':')[0]
         return {
-            'bucket': self.folder_id,
+            'bucket': bucket_name,
+            'id': self.folder_id,
             'encrypt_uploads': self.encrypt_uploads
         }
 
@@ -146,7 +173,7 @@ def create_waterbutler_log(self, auth, action, metadata):
         url = self.owner.web_url_for('addon_view_or_download_file', path=metadata['path'], provider='s3')
 
         self.owner.add_log(
-            's3_{0}'.format(action),
+            f's3_{action}',
             auth=auth,
             params={
                 'project': self.owner.parent_id,
diff --git a/addons/s3/provider.py b/addons/s3/provider.py
index ba28d065d54..0321a4a7d4e 100644
--- a/addons/s3/provider.py
+++ b/addons/s3/provider.py
@@ -1,6 +1,6 @@
 from addons.s3.serializer import S3Serializer
 
-class S3Provider(object):
+class S3Provider:
     """An alternative to `ExternalProvider` not tied to OAuth"""
 
     name = 'Amazon S3'
@@ -8,7 +8,7 @@ class S3Provider(object):
     serializer = S3Serializer
 
     def __init__(self, account=None):
-        super(S3Provider, self).__init__()
+        super().__init__()
 
         # provide an unauthenticated session by default
         self.account = account
diff --git a/addons/s3/requirements.txt b/addons/s3/requirements.txt
deleted file mode 100644
index 8e6ed87adf9..00000000000
--- a/addons/s3/requirements.txt
+++ /dev/null
@@ -1 +0,0 @@
-boto==2.38.0
diff --git a/addons/s3/settings/__init__.py b/addons/s3/settings/__init__.py
index 2b2f98881f6..40f955c5a78 100644
--- a/addons/s3/settings/__init__.py
+++ b/addons/s3/settings/__init__.py
@@ -7,4 +7,4 @@
 try:
     from .local import *  # noqa
 except ImportError:
-    logger.warn('No local.py settings file found')
+    logger.warning('No local.py settings file found')
diff --git a/addons/s3/settings/defaults.py b/addons/s3/settings/defaults.py
index 0b5cf009214..fbad8ff00a9 100644
--- a/addons/s3/settings/defaults.py
+++ b/addons/s3/settings/defaults.py
@@ -10,7 +10,7 @@
 MAX_RENDER_SIZE = (1024 ** 2) * 3
 
 # Max file size permitted by frontend in megabytes
-MAX_UPLOAD_SIZE = 50 * 1024  # 50 GB
+MAX_UPLOAD_SIZE = 5 * 1024  # 5 GB
 
 ALLOWED_ORIGIN = '*'
 
diff --git a/addons/s3/static/node-cfg.js b/addons/s3/static/node-cfg.js
index c7e33ca410a..ccef5f3e251 100644
--- a/addons/s3/static/node-cfg.js
+++ b/addons/s3/static/node-cfg.js
@@ -4,4 +4,4 @@ var s3NodeConfig = require('./s3NodeConfig.js').s3NodeConfig;
 
 var url = window.contextVars.node.urls.api + 's3/settings/';
 
-new s3NodeConfig('Amazon S3', '#s3Scope', url, '#s3Grid');
+new s3NodeConfig('Amazon S3', '#s3Scope', url, '#s3Grid');
\ No newline at end of file
diff --git a/addons/s3/static/s3-rubeus-cfg.js b/addons/s3/static/s3-rubeus-cfg.js
index 8493351f9ee..d76dcc8f744 100644
--- a/addons/s3/static/s3-rubeus-cfg.js
+++ b/addons/s3/static/s3-rubeus-cfg.js
@@ -1,47 +1,46 @@
-    var Rubeus = require('rubeus');
+var Rubeus = require('rubeus');
 
-    Rubeus.cfg.s3 = {
+Rubeus.cfg.s3 = {
 
-        uploadMethod: 'PUT',
-        uploadUrl: null,
-        uploadAdded: function(file, item) {
-            var self = this;
-            var parent = self.getByID(item.parentID);
-            var name = file.name;
-            // Make it possible to upload into subfolders
-            while (parent.depth > 1 && !parent.isAddonRoot) {
-                name = parent.name + '/' + name;
-                parent = self.getByID(parent.parentID);
-            }
-            file.destination = name;
-            file.signedUrlFrom = parent.urls.upload;
-        },
+    uploadMethod: 'PUT',
+    uploadUrl: null,
+    uploadAdded: function (file, item) {
+        var self = this;
+        var parent = self.getByID(item.parentID);
+        var name = file.name;
+        // Make it possible to upload into subfolders
+        while (parent.depth > 1 && !parent.isAddonRoot) {
+            name = parent.name + '/' + name;
+            parent = self.getByID(parent.parentID);
+        }
+        file.destination = name;
+        file.signedUrlFrom = parent.urls.upload;
+    },
 
-        uploadSending: function(file, formData, xhr) {
-            xhr.setRequestHeader('Content-Type', file.type || 'application/octet-stream');
-            xhr.setRequestHeader('x-amz-acl', 'private');
-        },
+    uploadSending: function (file, formData, xhr) {
+        xhr.setRequestHeader('Content-Type', file.type || 'application/octet-stream');
+        xhr.setRequestHeader('x-amz-acl', 'private');
+    },
 
-        uploadSuccess: function(file, row) {
-            var self = this;
-            var parent = this.getByID(row.parentID);
-            row.urls = {
-                'delete': parent.nodeApiUrl + 's3/' + file.destination + '/',
-                'download': parent.nodeUrl + 's3/' + file.destination + '/download/',
-                'view': parent.nodeUrl + 's3/' + file.destination + '/'
-            };
-            row.permissions = parent.permissions;
-            this.updateItem(row);
-            var updated = Rubeus.Utils.itemUpdated(row, parent);
-            if (updated) {
-                self.changeStatus(row, Rubeus.Status.UPDATED);
-                self.delayRemoveRow(row);
-            } else {
-                self.changeStatus(row, Rubeus.Status.UPLOAD_SUCCESS, null, 2000,
-                    function(row) {
-                        self.showButtons(row);
-                    });
-            }
+    uploadSuccess: function (file, row) {
+        var self = this;
+        var parent = this.getByID(row.parentID);
+        row.urls = {
+            'delete': parent.nodeApiUrl + 's3/' + file.destination + '/',
+            'download': parent.nodeUrl + 's3/' + file.destination + '/download/',
+            'view': parent.nodeUrl + 's3/' + file.destination + '/'
+        };
+        row.permissions = parent.permissions;
+        this.updateItem(row);
+        var updated = Rubeus.Utils.itemUpdated(row, parent);
+        if (updated) {
+            self.changeStatus(row, Rubeus.Status.UPDATED);
+            self.delayRemoveRow(row);
+        } else {
+            self.changeStatus(row, Rubeus.Status.UPLOAD_SUCCESS, null, 2000,
+                function (row) {
+                    self.showButtons(row);
+                });
         }
-    };
-
+    }
+};
diff --git a/addons/s3/static/s3AnonymousLogActionList.json b/addons/s3/static/s3AnonymousLogActionList.json
index 788ddcfa5fd..9f470e89f03 100644
--- a/addons/s3/static/s3AnonymousLogActionList.json
+++ b/addons/s3/static/s3AnonymousLogActionList.json
@@ -1,11 +1,11 @@
 {
-    "s3_bucket_linked" : "A user linked an Amazon S3 bucket to a project",
-    "s3_bucket_unlinked" : "A user unselected an Amazon S3 bucket in a project",
-    "s3_file_added" : "A user added a file to an Amazon S3 bucket in a project",
-    "s3_file_removed" : "A user removed a file in an Amazon S3 bucket in a project",
-    "s3_file_updated" : "A user updated a file in an Amazon S3 bucket in a project",
-    "s3_folder_created" : "A user created a folder in an Amazon S3 in a project",
-    "s3_node_authorized" : "A user authorized the Amazon S3 addon for a project",
-    "s3_node_deauthorized" : "A user deauthorized the Amazon S3 addon for a project",
-    "s3_node_deauthorized_no_user" : "Amazon S3 addon for a project deauthorized"
-}
+    "s3_bucket_linked": "A user linked an Amazon S3 bucket to a project",
+    "s3_bucket_unlinked": "A user unselected an Amazon S3 bucket in a project",
+    "s3_file_added": "A user added a file to an Amazon S3 bucket in a project",
+    "s3_file_removed": "A user removed a file in an Amazon S3 bucket in a project",
+    "s3_file_updated": "A user updated a file in an Amazon S3 bucket in a project",
+    "s3_folder_created": "A user created a folder in an Amazon S3 in a project",
+    "s3_node_authorized": "A user authorized the Amazon S3 addon for a project",
+    "s3_node_deauthorized": "A user deauthorized the Amazon S3 addon for a project",
+    "s3_node_deauthorized_no_user": "Amazon S3 addon for a project deauthorized"
+}
\ No newline at end of file
diff --git a/addons/s3/static/s3LogActionList.json b/addons/s3/static/s3LogActionList.json
index f2dc7ceef05..63d88ca3ba7 100644
--- a/addons/s3/static/s3LogActionList.json
+++ b/addons/s3/static/s3LogActionList.json
@@ -1,11 +1,11 @@
 {
-  "s3_bucket_linked" : "${user} linked the Amazon S3 bucket ${bucket} to ${node}",
-  "s3_bucket_unlinked" : "${user} unselected the Amazon S3 bucket ${bucket} in ${node}",
-  "s3_file_added" : "${user} added file ${path} to Amazon S3 bucket ${bucket} in ${node}",
-  "s3_file_removed" : "${user} removed ${path} in Amazon S3 bucket ${bucket} in ${node}",
-  "s3_file_updated" : "${user} updated file ${path} in Amazon S3 bucket ${bucket} in ${node}",
-  "s3_folder_created" : "${user} created folder ${path} in Amazon S3 bucket ${bucket} in ${node}",
-  "s3_node_authorized" : "${user} authorized the Amazon S3 addon for ${node}",
-  "s3_node_deauthorized" : "${user} deauthorized the Amazon S3 addon for ${node}",
-  "s3_node_deauthorized_no_user" : "Amazon S3 addon for ${node} deauthorized"
-}
+  "s3_bucket_linked": "${user} linked the Amazon S3 bucket ${bucket} to ${node}",
+  "s3_bucket_unlinked": "${user} unselected the Amazon S3 bucket ${bucket} in ${node}",
+  "s3_file_added": "${user} added file ${path} to Amazon S3 bucket ${bucket} in ${node}",
+  "s3_file_removed": "${user} removed ${path} in Amazon S3 bucket ${bucket} in ${node}",
+  "s3_file_updated": "${user} updated file ${path} in Amazon S3 bucket ${bucket} in ${node}",
+  "s3_folder_created": "${user} created folder ${path} in Amazon S3 bucket ${bucket} in ${node}",
+  "s3_node_authorized": "${user} authorized the Amazon S3 addon for ${node}",
+  "s3_node_deauthorized": "${user} deauthorized the Amazon S3 addon for ${node}",
+  "s3_node_deauthorized_no_user": "Amazon S3 addon for ${node} deauthorized"
+}
\ No newline at end of file
diff --git a/addons/s3/static/s3NodeConfig.js b/addons/s3/static/s3NodeConfig.js
index f5369691dfb..071deaed584 100644
--- a/addons/s3/static/s3NodeConfig.js
+++ b/addons/s3/static/s3NodeConfig.js
@@ -15,7 +15,7 @@ var OauthAddonFolderPicker = require('js/oauthAddonNodeConfig')._OauthAddonNodeC
 var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
     bucketLocations: s3Settings.bucketLocations,
 
-    constructor: function(addonName, url, selector, folderPicker, opts, tbOpts) {
+    constructor: function (addonName, url, selector, folderPicker, opts, tbOpts) {
         var self = this;
         self.super.constructor(addonName, url, selector, folderPicker, tbOpts);
         // Non-OAuth fields
@@ -26,9 +26,9 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
             {},
             OauthAddonFolderPicker.prototype.treebeardOptions,
             {   // TreeBeard Options
-                columnTitles: function() {
+                columnTitles: function () {
                     return [{
-                        title: 'Buckets',
+                        title: 'Buckets/Folders',
                         width: '75%',
                         sort: false
                     }, {
@@ -37,30 +37,24 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
                         sort: false
                     }];
                 },
-                resolveToggle: function(item) {
-                    return '';
-                },
-                resolveIcon: function(item) {
-                    return m('i.fa.fa-folder-o', ' ');
-                },
             },
             tbOpts
         );
     },
 
-    connectAccount: function() {
+    connectAccount: function () {
         var self = this;
-        if( !self.accessKey() && !self.secretKey() ){
+        if (!self.accessKey() && !self.secretKey()) {
             self.changeMessage('Please enter both an API access key and secret key.', 'text-danger');
             return;
         }
 
-        if (!self.accessKey() ){
+        if (!self.accessKey()) {
             self.changeMessage('Please enter an API access key.', 'text-danger');
             return;
         }
 
-        if (!self.secretKey() ){
+        if (!self.secretKey()) {
             self.changeMessage('Please enter an API secret key.', 'text-danger');
             return;
         }
@@ -68,17 +62,17 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
 
         return $osf.postJSON(
             self.urls().create, {
-                secret_key: self.secretKey(),
-                access_key: self.accessKey()
-            }
-        ).done(function(response) {
+            secret_key: self.secretKey(),
+            access_key: self.accessKey()
+        }
+        ).done(function (response) {
             $osf.unblock();
             self.clearModal();
             $('#s3InputCredentials').modal('hide');
             self.changeMessage('Successfully added S3 credentials.', 'text-success', null, true);
             self.updateFromData(response);
             self.importAuth();
-        }).fail(function(xhr, status, error) {
+        }).fail(function (xhr, status, error) {
             $osf.unblock();
             var message = '';
             var response = JSON.parse(xhr.responseText);
@@ -110,7 +104,7 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
      * @param {String} bucketName user-provided name of bucket to validate
      * @param {Boolean} laxChecking whether to use the more permissive validation
      */
-    isValidBucketName: function(bucketName, laxChecking) {
+    isValidBucketName: function (bucketName, laxChecking) {
         if (laxChecking === true) {
             return /^[a-zA-Z0-9.\-_]{1,255}$/.test(bucketName);
         }
@@ -122,7 +116,7 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
     },
 
     /** Reset all fields from S3 credentials input modal */
-    clearModal: function() {
+    clearModal: function () {
         var self = this;
         self.message('');
         self.messageClass('text-info');
@@ -130,22 +124,22 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
         self.accessKey(null);
     },
 
-    createBucket: function(self, bucketName, bucketLocation) {
+    createBucket: function (self, bucketName, bucketLocation) {
         $osf.block();
         bucketName = bucketName.toLowerCase();
         return $osf.postJSON(
             self.urls().createBucket, {
-                bucket_name: bucketName,
-                bucket_location: bucketLocation
-            }
-        ).done(function(response) {
+            bucket_name: bucketName,
+            bucket_location: bucketLocation
+        }
+        ).done(function (response) {
             $osf.unblock();
             self.loadedFolders(false);
             self.activatePicker();
             var msg = 'Successfully created bucket "' + $osf.htmlEscape(bucketName) + '". You can now select it from the list.';
             var msgType = 'text-success';
             self.changeMessage(msg, msgType, null, true);
-        }).fail(function(xhr) {
+        }).fail(function (xhr) {
             var resp = JSON.parse(xhr.responseText);
             var message = resp.message;
             var title = resp.title || 'Problem creating bucket';
@@ -156,21 +150,21 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
             bootbox.confirm({
                 title: $osf.htmlEscape(title),
                 message: $osf.htmlEscape(message),
-                callback: function(result) {
+                callback: function (result) {
                     if (result) {
                         self.openCreateBucket();
                     }
                 },
-                buttons:{
-                    confirm:{
-                        label:'Try again'
+                buttons: {
+                    confirm: {
+                        label: 'Try again'
                     }
                 }
             });
         });
     },
 
-    openCreateBucket: function() {
+    openCreateBucket: function () {
         var self = this;
 
         // Generates html options for key-value pairs in BUCKET_LOCATION_MAP
@@ -187,32 +181,32 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
         bootbox.dialog({
             title: 'Create a new bucket',
             message:
-                    '<div class="row"> ' +
-                        '<div class="col-md-12"> ' +
-                            '<form class="form-horizontal" onsubmit="return false"> ' +
-                                '<div class="form-group"> ' +
-                                    '<label class="col-md-4 control-label" for="bucketName">Bucket Name</label> ' +
-                                    '<div class="col-md-8"> ' +
-                                        '<input id="bucketName" name="bucketName" type="text" placeholder="Enter bucket name" class="form-control" autofocus> ' +
-                                        '<div>' +
-                                            '<span id="bucketModalErrorMessage" ></span>' +
-                                        '</div>'+
-                                    '</div>' +
-                                '</div>' +
-                                '<div class="form-group"> ' +
-                                    '<label class="col-md-4 control-label" for="bucketLocation">Bucket Location</label> ' +
-                                    '<div class="col-md-8"> ' +
-                                        '<select id="bucketLocation" name="bucketLocation" class="form-control"> ' +
-                                            generateBucketOptions(self.bucketLocations) +
-                                        '</select>' +
-                                    '</div>' +
-                                '</div>' +
-                            '</form>' +
-                            '<span>For more information on locations, click ' +
-                                '<a href="http://help.osf.io/m/addons/l/863985">here</a>' +
-                            '</span>' +
-                        '</div>' +
-                    '</div>',
+                '<div class="row"> ' +
+                '<div class="col-md-12"> ' +
+                '<form class="form-horizontal" onsubmit="return false"> ' +
+                '<div class="form-group"> ' +
+                '<label class="col-md-4 control-label" for="bucketName">Bucket Name</label> ' +
+                '<div class="col-md-8"> ' +
+                '<input id="bucketName" name="bucketName" type="text" placeholder="Enter bucket name" class="form-control" autofocus> ' +
+                '<div>' +
+                '<span id="bucketModalErrorMessage" ></span>' +
+                '</div>' +
+                '</div>' +
+                '</div>' +
+                '<div class="form-group"> ' +
+                '<label class="col-md-4 control-label" for="bucketLocation">Bucket Location</label> ' +
+                '<div class="col-md-8"> ' +
+                '<select id="bucketLocation" name="bucketLocation" class="form-control"> ' +
+                generateBucketOptions(self.bucketLocations) +
+                '</select>' +
+                '</div>' +
+                '</div>' +
+                '</form>' +
+                '<span>See <a href="http://help.osf.io/m/addons/l/863985">more ' +
+                'information on locations</a>' +
+                '</span>' +
+                '</div>' +
+                '</div>',
             buttons: {
                 cancel: {
                     label: 'Cancel',
@@ -234,7 +228,7 @@ var s3FolderPickerViewModel = oop.extend(OauthAddonFolderPicker, {
                             bootbox.confirm({
                                 title: 'Invalid bucket name',
                                 message: 'Amazon S3 buckets can contain lowercase letters, numbers, and hyphens separated by' +
-                                ' periods.  Please try another name.',
+                                    ' periods.  Please try another name.',
                                 callback: function (result) {
                                     if (result) {
                                         self.openCreateBucket();
@@ -271,4 +265,4 @@ function s3NodeConfig(addonName, selector, url, folderPicker, opts, tbOpts) {
 module.exports = {
     s3NodeConfig: s3NodeConfig,
     _s3NodeConfigViewModel: s3FolderPickerViewModel
-};
+};
\ No newline at end of file
diff --git a/addons/s3/static/s3UserConfig.js b/addons/s3/static/s3UserConfig.js
index 5489bc93ca8..ed9c4d433b2 100644
--- a/addons/s3/static/s3UserConfig.js
+++ b/addons/s3/static/s3UserConfig.js
@@ -32,26 +32,26 @@ function ViewModel(url) {
     ChangeMessageMixin.call(self);
 
     /** Reset all fields from S3 credentials input modal */
-    self.clearModal = function() {
+    self.clearModal = function () {
         self.message('');
         self.messageClass('text-info');
         self.accessKey(null);
         self.secretKey(null);
     };
     /** Send POST request to authorize S3 */
-    self.connectAccount = function() {
+    self.connectAccount = function () {
         // Selection should not be empty
-        if( !self.accessKey() && !self.secretKey() ){
+        if (!self.accessKey() && !self.secretKey()) {
             self.changeMessage('Please enter both an API access key and secret key.', 'text-danger');
             return;
         }
 
-        if (!self.accessKey() ){
+        if (!self.accessKey()) {
             self.changeMessage('Please enter an API access key.', 'text-danger');
             return;
         }
 
-        if (!self.secretKey() ){
+        if (!self.secretKey()) {
             self.changeMessage('Please enter an API secret key.', 'text-danger');
             return;
         }
@@ -61,12 +61,12 @@ function ViewModel(url) {
                 access_key: self.accessKey,
                 secret_key: self.secretKey,
             })
-        ).done(function() {
+        ).done(function () {
             self.clearModal();
             $modal.modal('hide');
             self.updateAccounts();
 
-        }).fail(function(xhr, textStatus, error) {
+        }).fail(function (xhr, textStatus, error) {
             var errorMessage = (xhr.status === 400 && xhr.responseJSON.message !== undefined) ? xhr.responseJSON.message : language.authError;
             self.changeMessage(errorMessage, 'text-danger');
             Raven.captureMessage('Could not authenticate with S3', {
@@ -79,20 +79,20 @@ function ViewModel(url) {
         });
     };
 
-    self.updateAccounts = function() {
+    self.updateAccounts = function () {
         return $.ajax({
             url: url,
             type: 'GET',
             dataType: 'json'
         }).done(function (data) {
-            self.accounts($.map(data.accounts, function(account) {
-                var externalAccount =  new ExternalAccount(account);
+            self.accounts($.map(data.accounts, function (account) {
+                var externalAccount = new ExternalAccount(account);
                 externalAccount.accessKey = account.oauth_key;
                 externalAccount.secretKey = account.oauth_secret;
                 return externalAccount;
             }));
-            $('#s3-header').osfToggleHeight({height: 160});
-        }).fail(function(xhr, status, error) {
+            $('#s3-header').osfToggleHeight({ height: 160 });
+        }).fail(function (xhr, status, error) {
             self.changeMessage(language.userSettingsError, 'text-danger');
             Raven.captureMessage('Error while updating addon account', {
                 extra: {
@@ -104,7 +104,7 @@ function ViewModel(url) {
         });
     };
 
-    self.askDisconnect = function(account) {
+    self.askDisconnect = function (account) {
         var self = this;
         bootbox.confirm({
             title: 'Disconnect Amazon S3 Account?',
@@ -117,26 +117,26 @@ function ViewModel(url) {
                     self.disconnectAccount(account);
                 }
             },
-            buttons:{
-                confirm:{
-                    label:'Disconnect',
-                    className:'btn-danger'
+            buttons: {
+                confirm: {
+                    label: 'Disconnect',
+                    className: 'btn-danger'
                 }
             }
         });
     };
 
-    self.disconnectAccount = function(account) {
+    self.disconnectAccount = function (account) {
         var self = this;
         var url = '/api/v1/oauth/accounts/' + account.id + '/';
         var request = $.ajax({
             url: url,
             type: 'DELETE'
         });
-        request.done(function(data) {
+        request.done(function (data) {
             self.updateAccounts();
         });
-        request.fail(function(xhr, status, error) {
+        request.fail(function (xhr, status, error) {
             Raven.captureMessage('Error while removing addon authorization for ' + account.id, {
                 extra: {
                     url: url,
@@ -148,8 +148,8 @@ function ViewModel(url) {
         return request;
     };
 
-    self.selectionChanged = function() {
-        self.changeMessage('','');
+    self.selectionChanged = function () {
+        self.changeMessage('', '');
     };
 
     self.updateAccounts();
@@ -170,4 +170,4 @@ function S3UserConfig(selector, url) {
 module.exports = {
     S3ViewModel: ViewModel,
     S3UserConfig: S3UserConfig
-};
+};
\ No newline at end of file
diff --git a/addons/s3/static/settings.json b/addons/s3/static/settings.json
index 05ea9dc29c5..1a5060a1ae4 100644
--- a/addons/s3/static/settings.json
+++ b/addons/s3/static/settings.json
@@ -16,4 +16,4 @@
         "sa-east-1": "Sao Paulo"
     },
     "encryptUploads": true
-}
+}
\ No newline at end of file
diff --git a/addons/s3/static/user-cfg.js b/addons/s3/static/user-cfg.js
index 48e6c1894e5..474aa68ca73 100644
--- a/addons/s3/static/user-cfg.js
+++ b/addons/s3/static/user-cfg.js
@@ -3,4 +3,4 @@ var S3UserConfig = require('./s3UserConfig.js').S3UserConfig;
 // Endpoint for S3 user settings
 var url = '/api/v1/settings/s3/accounts/';
 
-var s3UserConfig = new S3UserConfig('#s3AddonScope', url);
+var s3UserConfig = new S3UserConfig('#s3AddonScope', url);
\ No newline at end of file
diff --git a/addons/s3/templates/s3_credentials_modal.mako b/addons/s3/templates/s3_credentials_modal.mako
index de0092a9035..60dc9dc84e7 100644
--- a/addons/s3/templates/s3_credentials_modal.mako
+++ b/addons/s3/templates/s3_credentials_modal.mako
@@ -3,7 +3,7 @@
         <div class="modal-content">
 
             <div class="modal-header">
-                <h3>${ _("Connect an Amazon S3 Account")}</h3>
+                <h3>Connect an Amazon S3 Account</h3>
             </div>
 
             <form>
@@ -14,11 +14,11 @@
 
                         <div class="col-sm-6">
                             <div class="form-group">
-                                <label for="s3Addon">${ _("Access Key")}</label>
+                                <label for="s3Addon">Access Key</label>
                                 <input class="form-control" data-bind="value: accessKey" id="access_key" name="access_key" ${'disabled' if disabled else ''} />
                             </div>
                             <div class="form-group">
-                                <label for="s3Addon">${ _("Secret Key")}</label>
+                                <label for="s3Addon">Secret Key</label>
                                 <input type="password" class="form-control" data-bind="value: secretKey" id="secret_key" name="secret_key" ${'disabled' if disabled else ''} />
                             </div>
                         </div>
@@ -33,10 +33,10 @@
 
                 <div class="modal-footer">
 
-                    <a href="#" class="btn btn-default" data-bind="click: clearModal" data-dismiss="modal">${ _("Cancel")}</a>
+                    <a href="#" class="btn btn-default" data-bind="click: clearModal" data-dismiss="modal">Cancel</a>
 
                     <!-- Save Button -->
-                    <button data-bind="click: connectAccount" class="btn btn-success">${ _("Save")}</button>
+                    <button data-bind="click: connectAccount" class="btn btn-success">Save</button>
 
                 </div><!-- end modal-footer -->
 
@@ -44,4 +44,4 @@
 
         </div><!-- end modal-content -->
     </div>
-</div>
+</div>
\ No newline at end of file
diff --git a/addons/s3/templates/s3_node_settings.mako b/addons/s3/templates/s3_node_settings.mako
index 809d86dbb2e..25a4eb3bf61 100644
--- a/addons/s3/templates/s3_node_settings.mako
+++ b/addons/s3/templates/s3_node_settings.mako
@@ -4,35 +4,35 @@
     <%include file="s3_credentials_modal.mako"/>
 
     <h4 class="addon-title">
-        <img class="addon-icon" src=${addon_icon_url}>
+        <img class="addon-icon" src=${addon_icon_url} aria-label="${addon_full_name} icon" alt="${addon_full_name} icon">
         ${addon_full_name}
         <small class="authorized-by">
             <span data-bind="if: nodeHasAuth">
                 authorized by <a data-bind="attr: {href: urls().owner}, text: ownerName"></a>
                 % if not is_registration:
                     <a data-bind="click: deauthorize, visible: validCredentials"
-                        class="text-danger pull-right addon-auth">${_("Disconnect Account")}</a>
+                        class="text-danger pull-right addon-auth">Disconnect Account</a>
                 % endif
             </span>
 
              <!-- Import Access Token Button -->
             <span data-bind="if: showImport">
                 <a data-bind="click: importAuth" href="#" class="text-primary pull-right addon-auth">
-                    ${_("Import Account from Profile")}
+                    Import Account from Profile
                 </a>
             </span>
 
             <!-- Loading Import Text -->
             <span data-bind="if: showLoading">
                 <p class="text-muted pull-right addon-auth">
-                    ${_("Loading ...")}
+                    Loading ...
                 </p>
             </span>
 
-            <!-- Oauth Start Button -->
+            <!-- OAuth Start Button -->
             <span data-bind="if: showTokenCreateButton">
                 <a href="#s3InputCredentials" data-toggle="modal" class="pull-right text-primary addon-auth">
-                    ${_("Connect  Account")}
+                    Connect  Account
                 </a>
             </span>
         </small>
@@ -47,7 +47,7 @@
                         <a data-bind="attr: {href: urls().files}, text: folderName"></a>
                     </span>
                     <span class="text-muted" data-bind="ifnot: folderName">
-                        ${_("None")}
+                        None
                     </span>
                 </p>
                 <!-- Folder buttons -->
@@ -55,12 +55,12 @@
                     <button data-bind="click: togglePicker,
                                        css: {active: currentDisplay() === PICKER}" class="btn btn-primary">
                                        <span data-bind="text: toggleChangeText"></span></button>
-                    <button data-bind="visible: userIsOwner() && validCredentials(), click: openCreateBucket" class="btn btn-success" id="newBucket">${_("Create bucket")}</button>
+                    <button data-bind="visible: userIsOwner() && validCredentials(), click: openCreateBucket" class="btn btn-success" id="newBucket">Create bucket</button>
                 </div>
                 <!-- Folder picker -->
                 <div class="m-t-sm addon-folderpicker-widget ${addon_short_name}-widget">
                     <p class="text-muted text-center ${addon_short_name}-loading-text" data-bind="visible: loading">
-                        ${_("Loading buckets...")}</p>
+                        Loading buckets...</p>
                     <div data-bind="visible: currentDisplay() === PICKER">
                         <div id="${addon_short_name}Grid" class="filebrowser ${addon_short_name}-folder-picker"></div>
                     </div>
@@ -69,14 +69,14 @@
                         <form data-bind="submit: submitSettings">
                             <div class="break-word">
                                 <div data-bind="if: selected" class="alert alert-info ${addon_short_name}-confirm-dlg">
-                                    ${_("Connect %(folderName)s?") % dict(folderName='<b>&ldquo;<span data-bind="text: selectedFolderName"></span>&rdquo;</b>') | n}
+                                    Connect <b>&ldquo;<span data-bind="text: selectedFolderName"></span>&rdquo;</b>?
                                 </div>
                             </div>
                             <div class="pull-right">
                                 <button class="btn btn-default" data-bind="click: cancelSelection">
-                                    ${_("Cancel")}
+                                    Cancel
                                 </button>
-                                <input type="submit" class="btn btn-success" value="${_('Save')}" />
+                                <input type="submit" class="btn btn-success" value="Save" />
                             </div>
                         </form>
                     </div>
@@ -90,4 +90,4 @@
     <div class="help-block">
         <p data-bind="html: message, attr: {class: messageClass}"></p>
     </div>
-</div>
+</div>
\ No newline at end of file
diff --git a/addons/s3/templates/s3_user_settings.mako b/addons/s3/templates/s3_user_settings.mako
index dc4274d9319..5d95c2df2c5 100644
--- a/addons/s3/templates/s3_user_settings.mako
+++ b/addons/s3/templates/s3_user_settings.mako
@@ -6,22 +6,22 @@
     <%include file="s3_credentials_modal.mako"/>
 
     <h4 class="addon-title">
-        <img class="addon-icon" src=${addon_icon_url}>
+        <img class="addon-icon" src=${addon_icon_url} aria-label="${addon_full_name} icon" alt="${addon_full_name} icon">
         <span data-bind="text: properName"></span>
         <small>
-            <a href="#s3InputCredentials" data-toggle="modal" class="pull-right text-primary">${_("Connect or Reauthorize Account")}</a>
+            <a href="#s3InputCredentials" data-toggle="modal" class="pull-right text-primary">Connect or Reauthorize Account</a>
         </small>
     </h4>
 
     <div class="addon-auth-table" id="${addon_short_name}-header">
         <!-- ko foreach: accounts -->
-        <a data-bind="click: $root.askDisconnect.bind($root)" class="text-danger pull-right default-authorized-by">${_("Disconnect Account")}</a>
+        <a data-bind="click: $root.askDisconnect.bind($root)" class="text-danger pull-right default-authorized-by">Disconnect Account</a>
 
         <div class="m-h-lg">
             <table class="table table-hover">
                 <thead>
                     <tr class="user-settings-addon-auth">
-                        <th class="text-muted default-authorized-by">${_("Authorized by ")}<em><span data-bind="text: name"></span></em></th><th></th>
+                        <th class="default-authorized-by">Authorized by <em><span data-bind="text: name"></span></em></th><th></th>
                     </tr>
                 </thead>
                 <!-- ko if: connectedNodes().length > 0 -->
@@ -29,11 +29,11 @@
                     <tr>
                         <td class="authorized-nodes">
                             <!-- ko if: title --><a data-bind="attr: {href: urls.view}, text: title"></a><!-- /ko -->
-                            <!-- ko if: !title --><em>${_("Private project")}</em><!-- /ko -->
+                            <!-- ko if: !title --><em>Private project</em><!-- /ko -->
                         </td>
                         <td>
                             <a data-bind="click: $parent.deauthorizeNode.bind($parent)">
-                                <i class="fa fa-times text-danger pull-right" title="${_('disconnect Project')}"></i>
+                                <i class="fa fa-times text-danger pull-right" title="disconnect Project"></i>
                             </a>
                         </td>
                     </tr>
@@ -43,4 +43,4 @@
         </div>
         <!-- /ko -->
     </div>
-</div>
+</div>
\ No newline at end of file
diff --git a/addons/s3/tests/factories.py b/addons/s3/tests/factories.py
index a8b49856d47..bafdbaf9c84 100644
--- a/addons/s3/tests/factories.py
+++ b/addons/s3/tests/factories.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Factories for the S3 addon."""
 import factory
 from factory.django import DjangoModelFactory
@@ -11,9 +10,9 @@
 
 class S3AccountFactory(ExternalAccountFactory):
     provider = 's3'
-    provider_id = factory.Sequence(lambda n: 'id-{0}'.format(n))
-    oauth_key = factory.Sequence(lambda n: 'key-{0}'.format(n))
-    oauth_secret = factory.Sequence(lambda n: 'secret-{0}'.format(n))
+    provider_id = factory.Sequence(lambda n: f'id-{n}')
+    oauth_key = factory.Sequence(lambda n: f'key-{n}')
+    oauth_secret = factory.Sequence(lambda n: f'secret-{n}')
     display_name = 'S3 Fake User'
 
 
diff --git a/addons/s3/tests/test_model.py b/addons/s3/tests/test_model.py
index b616a66c652..af608f5cc8a 100644
--- a/addons/s3/tests/test_model.py
+++ b/addons/s3/tests/test_model.py
@@ -1,7 +1,4 @@
-# from nose.tools import *  # noqa
-import mock
-from nose.tools import (assert_false, assert_true,
-    assert_equal, assert_is_none)
+from unittest import mock
 import pytest
 import unittest
 
@@ -38,26 +35,33 @@ class TestNodeSettings(OAuthAddonNodeSettingsTestSuiteMixin, unittest.TestCase):
     NodeSettingsClass = NodeSettings
     UserSettingsFactory = S3UserSettingsFactory
 
+    def _node_settings_class_kwargs(self, node, user_settings):
+        return {
+            'user_settings': self.user_settings,
+            'folder_id': 'bucket_name:/path_goes_here/with_folder_id',
+            'owner': self.node
+        }
+
     def test_registration_settings(self):
         registration = ProjectFactory()
         clone, message = self.node_settings.after_register(
             self.node, registration, self.user,
         )
-        assert_is_none(clone)
+        assert clone is None
 
     def test_before_register_no_settings(self):
         self.node_settings.user_settings = None
         message = self.node_settings.before_register(self.node, self.user)
-        assert_false(message)
+        assert not message
 
     def test_before_register_no_auth(self):
         self.node_settings.external_account = None
         message = self.node_settings.before_register(self.node, self.user)
-        assert_false(message)
+        assert not message
 
     def test_before_register_settings_and_auth(self):
         message = self.node_settings.before_register(self.node, self.user)
-        assert_true(message)
+        assert message
 
     @mock.patch('website.archiver.tasks.archive')
     def test_does_not_get_copied_to_registrations(self, mock_archive):
@@ -66,7 +70,7 @@ def test_does_not_get_copied_to_registrations(self, mock_archive):
             auth=Auth(user=self.user),
             draft_registration=DraftRegistrationFactory(branched_from=self.node),
         )
-        assert_false(registration.has_addon('s3'))
+        assert not registration.has_addon('s3')
 
     ## Overrides ##
 
@@ -78,7 +82,7 @@ def test_serialize_credentials(self):
 
         expected = {'access_key': self.node_settings.external_account.oauth_key,
                     'secret_key': self.node_settings.external_account.oauth_secret}
-        assert_equal(credentials, expected)
+        assert credentials == expected
 
     @mock.patch('addons.s3.models.bucket_exists')
     @mock.patch('addons.s3.models.get_bucket_location_or_error')
@@ -89,13 +93,16 @@ def test_set_folder(self, mock_location, mock_exists):
         self.node_settings.set_folder(folder_id, auth=Auth(self.user))
         self.node_settings.save()
         # Bucket was set
-        assert_equal(self.node_settings.folder_id, folder_id)
+        assert self.node_settings.folder_id == folder_id
         # Log was saved
         last_log = self.node.logs.latest()
-        assert_equal(last_log.action, '{0}_bucket_linked'.format(self.short_name))
+        assert last_log.action == f'{self.short_name}_bucket_linked'
 
     def test_serialize_settings(self):
         settings = self.node_settings.serialize_waterbutler_settings()
-        expected = {'bucket': self.node_settings.folder_id,
-                    'encrypt_uploads': self.node_settings.encrypt_uploads}
-        assert_equal(settings, expected)
+        expected = {
+            'bucket': 'bucket_name',
+            'encrypt_uploads': self.node_settings.encrypt_uploads,
+            'id': 'bucket_name:/path_goes_here/with_folder_id'
+        }
+        assert settings == expected
diff --git a/addons/s3/tests/test_serializer.py b/addons/s3/tests/test_serializer.py
index a1c637020c3..f1fa025d49c 100644
--- a/addons/s3/tests/test_serializer.py
+++ b/addons/s3/tests/test_serializer.py
@@ -1,6 +1,5 @@
-# -*- coding: utf-8 -*-
 """Serializer tests for the S3 addon."""
-import mock
+from unittest import mock
 import pytest
 
 from addons.base.tests.serializers import StorageAddonSerializerTestSuiteMixin
@@ -24,8 +23,8 @@ def setUp(self):
         self.mock_can_list = mock.patch('addons.s3.serializer.utils.can_list')
         self.mock_can_list.return_value = True
         self.mock_can_list.start()
-        super(TestS3Serializer, self).setUp()
+        super().setUp()
 
     def tearDown(self):
         self.mock_can_list.stop()
-        super(TestS3Serializer, self).tearDown()
+        super().tearDown()
diff --git a/addons/s3/tests/test_view.py b/addons/s3/tests/test_view.py
index 8db2b2a9091..47b0ad9435d 100644
--- a/addons/s3/tests/test_view.py
+++ b/addons/s3/tests/test_view.py
@@ -1,15 +1,12 @@
-# -*- coding: utf-8 -*-
 from rest_framework import status as http_status
 
-from boto.exception import S3ResponseError
-import mock
-from nose.tools import (assert_equal, assert_equals,
-    assert_true, assert_in, assert_false)
+from botocore.exceptions import NoCredentialsError
+from unittest import mock
 import pytest
 
 from framework.auth import Auth
 from tests.base import OsfTestCase, get_default_metaschema
-from osf_tests.factories import ProjectFactory, AuthUserFactory, DraftRegistrationFactory, InstitutionFactory
+from osf_tests.factories import ProjectFactory, AuthUserFactory, DraftRegistrationFactory
 
 from addons.base.tests.views import (
     OAuthAddonConfigViewsTestCaseMixin
@@ -32,35 +29,35 @@ def setUp(self):
         self.mock_exists = mock.patch('addons.s3.views.utils.bucket_exists')
         self.mock_exists.return_value = True
         self.mock_exists.start()
-        super(TestS3Views, self).setUp()
+        super().setUp()
 
     def tearDown(self):
         self.mock_can_list.stop()
         self.mock_uid.stop()
         self.mock_exists.stop()
-        super(TestS3Views, self).tearDown()
+        super().tearDown()
 
     def test_s3_settings_input_empty_keys(self):
         url = self.project.api_url_for('s3_add_user_account')
-        rv = self.app.post_json(url, {
+        rv = self.app.post(url, json={
             'access_key': '',
             'secret_key': ''
-        }, auth=self.user.auth, expect_errors=True)
-        assert_equals(rv.status_int, http_status.HTTP_400_BAD_REQUEST)
-        assert_in('All the fields above are required.', rv.body.decode())
+        }, auth=self.user.auth, )
+        assert rv.status_code == http_status.HTTP_400_BAD_REQUEST
+        assert 'All the fields above are required.' in rv.text
 
     def test_s3_settings_input_empty_access_key(self):
         url = self.project.api_url_for('s3_add_user_account')
-        rv = self.app.post_json(url, {
+        rv = self.app.post(url, json={
             'access_key': '',
             'secret_key': 'Non-empty-secret-key'
-        }, auth=self.user.auth, expect_errors=True)
-        assert_equals(rv.status_int, http_status.HTTP_400_BAD_REQUEST)
-        assert_in('All the fields above are required.', rv.body.decode())
+        }, auth=self.user.auth, )
+        assert rv.status_code == http_status.HTTP_400_BAD_REQUEST
+        assert 'All the fields above are required.' in rv.text
 
     def test_s3_settings_input_empty_secret_key(self):
         url = self.project.api_url_for('s3_add_user_account')
-        rv = self.app.post_json(url, {
+        rv = self.app.post(url, json={
             'access_key': 'Non-empty-access-key',
             'secret_key': ''
         }, auth=self.user.auth, expect_errors=True)
@@ -86,11 +83,10 @@ def test_s3_set_bucket_no_settings(self):
         user = AuthUserFactory()
         self.project.add_contributor(user, save=True)
         url = self.project.api_url_for('s3_set_config')
-        res = self.app.put_json(
-            url, {'s3_bucket': 'hammertofall'}, auth=user.auth,
-            expect_errors=True
+        res = self.app.put(
+            url, json={'s3_bucket': 'hammertofall'}, auth=user.auth,
         )
-        assert_equal(res.status_code, http_status.HTTP_400_BAD_REQUEST)
+        assert res.status_code == http_status.HTTP_400_BAD_REQUEST
 
     def test_s3_set_bucket_no_auth(self):
 
@@ -98,11 +94,10 @@ def test_s3_set_bucket_no_auth(self):
         user.add_addon('s3')
         self.project.add_contributor(user, save=True)
         url = self.project.api_url_for('s3_set_config')
-        res = self.app.put_json(
-            url, {'s3_bucket': 'hammertofall'}, auth=user.auth,
-            expect_errors=True
+        res = self.app.put(
+            url, json={'s3_bucket': 'hammertofall'}, auth=user.auth,
         )
-        assert_equal(res.status_code, http_status.HTTP_403_FORBIDDEN)
+        assert res.status_code == http_status.HTTP_403_FORBIDDEN
 
     def test_s3_set_bucket_registered(self):
         registration = self.project.register_node(
@@ -110,35 +105,34 @@ def test_s3_set_bucket_registered(self):
         )
 
         url = registration.api_url_for('s3_set_config')
-        res = self.app.put_json(
-            url, {'s3_bucket': 'hammertofall'}, auth=self.user.auth,
-            expect_errors=True,
+        res = self.app.put(
+            url, json={'s3_bucket': 'hammertofall'}, auth=self.user.auth,
         )
 
-        assert_equal(res.status_code, http_status.HTTP_400_BAD_REQUEST)
+        assert res.status_code == http_status.HTTP_400_BAD_REQUEST
 
     @mock.patch('addons.s3.views.utils.can_list', return_value=False)
     def test_user_settings_cant_list(self, mock_can_list):
         url = api_url_for('s3_add_user_account')
-        rv = self.app.post_json(url, {
+        rv = self.app.post(url, json={
             'access_key': 'aldkjf',
             'secret_key': 'las'
-        }, auth=self.user.auth, expect_errors=True)
+        }, auth=self.user.auth)
 
-        assert_in('Unable to list buckets.', rv.body.decode())
-        assert_equals(rv.status_int, http_status.HTTP_400_BAD_REQUEST)
+        assert 'Unable to list buckets.' in rv.text
+        assert rv.status_code == http_status.HTTP_400_BAD_REQUEST
 
     def test_s3_remove_node_settings_owner(self):
         url = self.node_settings.owner.api_url_for('s3_deauthorize_node')
         self.app.delete(url, auth=self.user.auth)
         result = self.Serializer().serialize_settings(node_settings=self.node_settings, current_user=self.user)
-        assert_equal(result['nodeHasAuth'], False)
+        assert result['nodeHasAuth'] == False
 
     def test_s3_remove_node_settings_unauthorized(self):
         url = self.node_settings.owner.api_url_for('s3_deauthorize_node')
-        ret = self.app.delete(url, auth=None, expect_errors=True)
+        ret = self.app.delete(url, auth=None, )
 
-        assert_equal(ret.status_code, 401)
+        assert ret.status_code == 401
 
     def test_s3_get_node_settings_owner(self):
         self.node_settings.set_auth(self.external_account, self.user)
@@ -148,23 +142,23 @@ def test_s3_get_node_settings_owner(self):
         res = self.app.get(url, auth=self.user.auth)
 
         result = res.json['result']
-        assert_equal(result['nodeHasAuth'], True)
-        assert_equal(result['userIsOwner'], True)
-        assert_equal(result['folder']['path'], self.node_settings.folder_id)
+        assert result['nodeHasAuth'] == True
+        assert result['userIsOwner'] == True
+        assert result['folder']['path'] == self.node_settings.folder_id
 
     def test_s3_get_node_settings_unauthorized(self):
         url = self.node_settings.owner.api_url_for('s3_get_config')
         unauthorized = AuthUserFactory()
-        ret = self.app.get(url, auth=unauthorized.auth, expect_errors=True)
+        ret = self.app.get(url, auth=unauthorized.auth, )
 
-        assert_equal(ret.status_code, 403)
+        assert ret.status_code == 403
 
     ## Overrides ##
 
     @mock.patch('addons.s3.models.get_bucket_names')
     def test_folder_list(self, mock_names):
         mock_names.return_value = ['bucket1', 'bucket2']
-        super(TestS3Views, self).test_folder_list()
+        super().test_folder_list()
 
     @mock.patch('addons.s3.models.bucket_exists')
     @mock.patch('addons.s3.models.get_bucket_location_or_error')
@@ -172,25 +166,22 @@ def test_set_config(self, mock_location, mock_exists):
         mock_exists.return_value = True
         mock_location.return_value = ''
         self.node_settings.set_auth(self.external_account, self.user)
-        url = self.project.api_url_for('{0}_set_config'.format(self.ADDON_SHORT_NAME))
-        res = self.app.put_json(url, {
+        url = self.project.api_url_for(f'{self.ADDON_SHORT_NAME}_set_config')
+        res = self.app.put(url, json={
             'selected': self.folder
         }, auth=self.user.auth)
-        assert_equal(res.status_code, http_status.HTTP_200_OK)
+        assert res.status_code == http_status.HTTP_200_OK
         self.project.reload()
         self.node_settings.reload()
-        assert_equal(
-            self.project.logs.latest().action,
-            '{0}_bucket_linked'.format(self.ADDON_SHORT_NAME)
-        )
-        assert_equal(res.json['result']['folder']['name'], self.node_settings.folder_name)
+        assert self.project.logs.latest().action == f'{self.ADDON_SHORT_NAME}_bucket_linked'
+        assert res.json['result']['folder']['name'] == self.node_settings.folder_name
 
 
 class TestCreateBucket(S3AddonTestCase, OsfTestCase):
 
     def setUp(self):
 
-        super(TestCreateBucket, self).setUp()
+        super().setUp()
 
         self.user = AuthUserFactory()
         self.consolidated_auth = Auth(user=self.user)
@@ -212,57 +203,57 @@ def setUp(self):
         self.node_settings.save()
 
     def test_bad_names(self):
-        assert_false(validate_bucket_name(''))
-        assert_false(validate_bucket_name('no'))
-        assert_false(validate_bucket_name('a' * 64))
-        assert_false(validate_bucket_name(' leadingspace'))
-        assert_false(validate_bucket_name('trailingspace '))
-        assert_false(validate_bucket_name('bogus naMe'))
-        assert_false(validate_bucket_name('.cantstartwithp'))
-        assert_false(validate_bucket_name('or.endwith.'))
-        assert_false(validate_bucket_name('..nodoubles'))
-        assert_false(validate_bucket_name('no_unders_in'))
-        assert_false(validate_bucket_name('-leadinghyphen'))
-        assert_false(validate_bucket_name('trailinghyphen-'))
-        assert_false(validate_bucket_name('Mixedcase'))
-        assert_false(validate_bucket_name('empty..label'))
-        assert_false(validate_bucket_name('label-.trailinghyphen'))
-        assert_false(validate_bucket_name('label.-leadinghyphen'))
-        assert_false(validate_bucket_name('8.8.8.8'))
-        assert_false(validate_bucket_name('600.9000.0.28'))
-        assert_false(validate_bucket_name('no_underscore'))
-        assert_false(validate_bucket_name('_nounderscoreinfront'))
-        assert_false(validate_bucket_name('no-underscore-in-back_'))
-        assert_false(validate_bucket_name('no-underscore-in_the_middle_either'))
+        assert not validate_bucket_name('')
+        assert not validate_bucket_name('no')
+        assert not validate_bucket_name('a' * 64)
+        assert not validate_bucket_name(' leadingspace')
+        assert not validate_bucket_name('trailingspace ')
+        assert not validate_bucket_name('bogus naMe')
+        assert not validate_bucket_name('.cantstartwithp')
+        assert not validate_bucket_name('or.endwith.')
+        assert not validate_bucket_name('..nodoubles')
+        assert not validate_bucket_name('no_unders_in')
+        assert not validate_bucket_name('-leadinghyphen')
+        assert not validate_bucket_name('trailinghyphen-')
+        assert not validate_bucket_name('Mixedcase')
+        assert not validate_bucket_name('empty..label')
+        assert not validate_bucket_name('label-.trailinghyphen')
+        assert not validate_bucket_name('label.-leadinghyphen')
+        assert not validate_bucket_name('8.8.8.8')
+        assert not validate_bucket_name('600.9000.0.28')
+        assert not validate_bucket_name('no_underscore')
+        assert not validate_bucket_name('_nounderscoreinfront')
+        assert not validate_bucket_name('no-underscore-in-back_')
+        assert not validate_bucket_name('no-underscore-in_the_middle_either')
 
     def test_names(self):
-        assert_true(validate_bucket_name('imagoodname'))
-        assert_true(validate_bucket_name('still.passing'))
-        assert_true(validate_bucket_name('can-have-dashes'))
-        assert_true(validate_bucket_name('kinda.name.spaced'))
-        assert_true(validate_bucket_name('a-o.valid'))
-        assert_true(validate_bucket_name('11.12.m'))
-        assert_true(validate_bucket_name('a--------a'))
-        assert_true(validate_bucket_name('a' * 63))
+        assert validate_bucket_name('imagoodname')
+        assert validate_bucket_name('still.passing')
+        assert validate_bucket_name('can-have-dashes')
+        assert validate_bucket_name('kinda.name.spaced')
+        assert validate_bucket_name('a-o.valid')
+        assert validate_bucket_name('11.12.m')
+        assert validate_bucket_name('a--------a')
+        assert validate_bucket_name('a' * 63)
 
     def test_bad_locations(self):
-        assert_false(validate_bucket_location('Venus'))
-        assert_false(validate_bucket_location('AlphaCentari'))
-        assert_false(validate_bucket_location('CostaRica'))
+        assert not validate_bucket_location('Venus')
+        assert not validate_bucket_location('AlphaCentauri')
+        assert not validate_bucket_location('CostaRica')
 
     def test_locations(self):
-        assert_true(validate_bucket_location(''))
-        assert_true(validate_bucket_location('eu-central-1'))
-        assert_true(validate_bucket_location('ca-central-1'))
-        assert_true(validate_bucket_location('us-west-1'))
-        assert_true(validate_bucket_location('us-west-2'))
-        assert_true(validate_bucket_location('ap-northeast-1'))
-        assert_true(validate_bucket_location('ap-northeast-2'))
-        assert_true(validate_bucket_location('ap-southeast-1'))
-        assert_true(validate_bucket_location('ap-southeast-2'))
-        assert_true(validate_bucket_location('sa-east-1'))
-        assert_true(validate_bucket_location('eu-west-1'))
-        assert_true(validate_bucket_location('eu-west-2'))
+        assert validate_bucket_location('')
+        assert validate_bucket_location('eu-central-1')
+        assert validate_bucket_location('ca-central-1')
+        assert validate_bucket_location('us-west-1')
+        assert validate_bucket_location('us-west-2')
+        assert validate_bucket_location('ap-northeast-1')
+        assert validate_bucket_location('ap-northeast-2')
+        assert validate_bucket_location('ap-southeast-1')
+        assert validate_bucket_location('ap-southeast-2')
+        assert validate_bucket_location('sa-east-1')
+        assert validate_bucket_location('eu-west-1')
+        assert validate_bucket_location('eu-west-2')
 
     @mock.patch('addons.s3.views.utils.create_bucket')
     @mock.patch('addons.s3.views.utils.get_bucket_names')
@@ -274,39 +265,37 @@ def test_create_bucket_pass(self, mock_names, mock_make):
             'doesntevenmatter'
         ]
         url = self.project.api_url_for('create_bucket')
-        ret = self.app.post_json(
+        ret = self.app.post(
             url,
-            {
+            json={
                 'bucket_name': 'doesntevenmatter',
                 'bucket_location': '',
             },
             auth=self.user.auth
         )
 
-        assert_equal(ret.status_int, http_status.HTTP_200_OK)
-        assert_equal(ret.json, {})
+        assert ret.status_code == http_status.HTTP_200_OK
+        assert ret.json == {}
 
     @mock.patch('addons.s3.views.utils.create_bucket')
     def test_create_bucket_fail(self, mock_make):
-        error = S3ResponseError(418, 'because Im a test')
-        error.message = 'This should work'
+        error = NoCredentialsError(operation_name='create_bucket')
         mock_make.side_effect = error
 
-        url = '/api/v1/project/{0}/s3/newbucket/'.format(self.project._id)
-        ret = self.app.post_json(url, {'bucket_name': 'doesntevenmatter'}, auth=self.user.auth, expect_errors=True)
+        url = f'/api/v1/project/{self.project._id}/s3/newbucket/'
+        ret = self.app.post(url, json={'bucket_name': 'doesntevenmatter'}, auth=self.user.auth)
 
-        assert_equals(ret.body.decode(), '{"message": "This should work", "title": "Problem connecting to S3"}')
+        assert ret.text == '{"message": "Unable to locate credentials", "title": "Problem connecting to S3"}'
 
     @mock.patch('addons.s3.views.utils.create_bucket')
     def test_bad_location_fails(self, mock_make):
-        url = '/api/v1/project/{0}/s3/newbucket/'.format(self.project._id)
-        ret = self.app.post_json(
+        url = f'/api/v1/project/{self.project._id}/s3/newbucket/'
+        ret = self.app.post(
             url,
-            {
+            json={
                 'bucket_name': 'doesntevenmatter',
                 'bucket_location': 'not a real bucket location',
             },
             auth=self.user.auth,
-            expect_errors=True)
-
-        assert_equals(ret.body.decode(), '{"message": "That bucket location is not valid.", "title": "Invalid bucket location"}')
+        )
+        assert ret.text == '{"message": "That bucket location is not valid.", "title": "Invalid bucket location"}'
diff --git a/addons/s3/tests/utils.py b/addons/s3/tests/utils.py
index 15b0153f23b..e83f4ebf489 100644
--- a/addons/s3/tests/utils.py
+++ b/addons/s3/tests/utils.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from addons.base.tests.base import OAuthAddonTestCaseMixin, AddonTestCase
 from addons.s3.tests.factories import S3AccountFactory
 from addons.s3.provider import S3Provider
diff --git a/addons/s3/utils.py b/addons/s3/utils.py
index 0738b5bf397..73d53ebf18e 100644
--- a/addons/s3/utils.py
+++ b/addons/s3/utils.py
@@ -1,14 +1,19 @@
 import re
+import logging
+from dataclasses import dataclass
+from typing import Optional  # Python 3.6 does not support | operator for type hints
+
 from rest_framework import status as http_status
 
-from boto import exception
-from boto.s3.connection import S3Connection
-from boto.s3.connection import OrdinaryCallingFormat
+import boto3
+from botocore import exceptions
 
 from framework.exceptions import HTTPError
 from addons.base.exceptions import InvalidAuthError, InvalidFolderError
 from addons.s3.settings import BUCKET_LOCATIONS
 
+logger = logging.getLogger(__name__)
+
 
 def connect_s3(access_key=None, secret_key=None, node_settings=None):
     """Helper to build an S3Connection object
@@ -18,19 +23,27 @@ def connect_s3(access_key=None, secret_key=None, node_settings=None):
     if node_settings is not None:
         if node_settings.external_account is not None:
             access_key, secret_key = node_settings.external_account.oauth_key, node_settings.external_account.oauth_secret
-    connection = S3Connection(access_key, secret_key, calling_format=OrdinaryCallingFormat())
+    connection = boto3.client(
+        's3',
+        aws_access_key_id=access_key,
+        aws_secret_access_key=secret_key
+    )
     return connection
 
 
+def get_status_for_error(e: exceptions.ClientError) -> int:
+    return e.response['ResponseMetadata']['HTTPStatusCode']
+
+
 def get_bucket_names(node_settings):
     try:
-        buckets = connect_s3(node_settings=node_settings).get_all_buckets()
-    except exception.NoAuthHandlerFound:
+        response = connect_s3(node_settings=node_settings).list_buckets()
+    except exceptions.NoCredentialsError:
         raise HTTPError(http_status.HTTP_403_FORBIDDEN)
-    except exception.BotoServerError as e:
-        raise HTTPError(e.status)
+    except exceptions.ClientError as e:
+        raise HTTPError(get_status_for_error(e))
 
-    return [bucket.name for bucket in buckets]
+    return [bucket['Name'] for bucket in response['Buckets']]
 
 
 def validate_bucket_location(location):
@@ -51,28 +64,34 @@ def validate_bucket_name(name):
 
 
 def create_bucket(node_settings, bucket_name, location=''):
-    return connect_s3(node_settings=node_settings).create_bucket(bucket_name, location=location)
+    client = connect_s3(node_settings=node_settings)
+
+    # default bucket location won't work with location constraint
+    if not location or location == 'us-east-1':
+        return client.create_bucket(Bucket=bucket_name)
+    else:
+        return client.create_bucket(
+            Bucket=bucket_name,
+            CreateBucketConfiguration={
+                'LocationConstraint': location,
+            }
+        )
 
 
 def bucket_exists(access_key, secret_key, bucket_name):
-    """Tests for the existance of a bucket and if the user
+    """Tests for the existence of a bucket and if the user
     can access it with the given keys
     """
     if not bucket_name:
         return False
-
-    connection = connect_s3(access_key, secret_key)
-
-    if bucket_name != bucket_name.lower():
-        # Must use ordinary calling format for mIxEdCaSe bucket names
-        # otherwise use the default as it handles bucket outside of the US
-        connection.calling_format = OrdinaryCallingFormat()
+    # bucket names are dns-compliant, therefore must be lowercase
+    bucket_name = bucket_name.lower()
 
     try:
         # Will raise an exception if bucket_name doesn't exist
-        connect_s3(access_key, secret_key).head_bucket(bucket_name)
-    except exception.S3ResponseError as e:
-        if e.status not in (301, 302):
+        connect_s3(access_key, secret_key).head_bucket(Bucket=bucket_name)
+    except exceptions.ClientError as e:
+        if get_status_for_error(e) not in (301, 302):
             return False
     return True
 
@@ -87,38 +106,73 @@ def can_list(access_key, secret_key):
         return False
 
     try:
-        connect_s3(access_key, secret_key).get_all_buckets()
-    except exception.S3ResponseError:
+        connect_s3(access_key, secret_key).list_buckets()
+    except exceptions.ClientError:
         return False
     return True
 
-def get_user_info(access_key, secret_key):
+
+@dataclass(frozen=True)  # slots is not supported in python 3.6
+class Owner:
+    __slots__ = ['display_name', 'id']
+
+    display_name: str
+    id: str
+
+    @classmethod
+    def from_dict(cls, data):
+        return cls(data['DisplayName'], data['ID'])
+
+
+def get_user_info(access_key: str, secret_key: str) -> Optional[Owner]:
     """Returns an S3 User with .display_name and .id, or None
     """
     if not (access_key and secret_key):
         return None
 
     try:
-        return connect_s3(access_key, secret_key).get_all_buckets().owner
-    except exception.S3ResponseError:
+        return Owner.from_dict(connect_s3(access_key, secret_key).list_buckets()['Owner'])
+    except exceptions.ClientError:
         return None
-    return None
+
 
 def get_bucket_location_or_error(access_key, secret_key, bucket_name):
     """Returns the location of a bucket or raises AddonError
     """
-    try:
-        connection = connect_s3(access_key, secret_key)
-    except Exception:
-        raise InvalidAuthError()
-
-    if bucket_name != bucket_name.lower() or '.' in bucket_name:
-        # Must use ordinary calling format for mIxEdCaSe bucket names
-        # otherwise use the default as it handles bucket outside of the US
-        connection.calling_format = OrdinaryCallingFormat()
+    # bucket names are dns-compliant, therefore must be lowercase
+    bucket_name = bucket_name.lower()
 
     try:
         # Will raise an exception if bucket_name doesn't exist
-        return connect_s3(access_key, secret_key).get_bucket(bucket_name, validate=False).get_location()
-    except exception.S3ResponseError:
+        return connect_s3(access_key, secret_key).get_bucket_location(Bucket=bucket_name)['LocationConstraint']
+    except exceptions.NoCredentialsError:
+        raise InvalidAuthError()
+    except exceptions.ClientError:
         raise InvalidFolderError()
+
+
+def get_bucket_prefixes(access_key, secret_key, prefix, bucket_name):
+    s3 = boto3.client(
+        's3',
+        aws_access_key_id=access_key,
+        aws_secret_access_key=secret_key
+    )
+
+    result = s3.list_objects(Bucket=bucket_name, Prefix=prefix, Delimiter='/')
+    folders = []
+    for common_prefixes in result.get('CommonPrefixes', []):
+        key_name = common_prefixes.get('Prefix')
+        if key_name != prefix:
+            folders.append(
+                {
+                    'path': key_name,
+                    'id': f'{bucket_name}:/{key_name}',
+                    'folder_id': key_name,
+                    'kind': 'folder',
+                    'bucket_name': bucket_name,
+                    'name': key_name.split('/')[-2],
+                    'addon': 's3',
+                }
+            )
+
+    return folders
diff --git a/addons/s3/views.py b/addons/s3/views.py
index 672dd335305..5aef084cd90 100644
--- a/addons/s3/views.py
+++ b/addons/s3/views.py
@@ -1,6 +1,6 @@
 from rest_framework import status as http_status
 
-from boto import exception
+from botocore import exceptions
 from django.core.exceptions import ValidationError
 from flask import request
 
@@ -58,7 +58,9 @@ def _set_folder(node_addon, folder, auth):
 def s3_folder_list(node_addon, **kwargs):
     """ Returns all the subsequent folders under the folder id passed.
     """
-    return node_addon.get_folders()
+    path = request.args.get('path', '')
+    folder_id = request.args.get('id', '')
+    return node_addon.get_folders(path=path, folder_id=folder_id)
 
 @must_be_logged_in
 @must_be_rdm_addons_allowed(SHORT_NAME)
@@ -148,20 +150,15 @@ def create_bucket(auth, node_addon, **kwargs):
 
     try:
         utils.create_bucket(node_addon, bucket_name, bucket_location)
-    except exception.S3ResponseError as e:
+    except exceptions.NoCredentialsError as e:
         return {
-            'message': e.message,
+            'message': str(e),
             'title': 'Problem connecting to S3',
         }, http_status.HTTP_400_BAD_REQUEST
-    except exception.S3CreateError as e:
+    except exceptions.ClientError as e:
         return {
-            'message': e.message,
-            'title': "Problem creating bucket '{0}'".format(bucket_name),
-        }, http_status.HTTP_400_BAD_REQUEST
-    except exception.BotoClientError as e:  # Base class catchall
-        return {
-            'message': e.message,
-            'title': 'Error connecting to S3',
+            'message': str(e),
+            'title': f"Problem creating bucket '{bucket_name}'",
         }, http_status.HTTP_400_BAD_REQUEST
 
     return {}
diff --git a/requirements.txt b/requirements.txt
index c9ee19ae23b..f3574223512 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -133,3 +133,5 @@ Babel==2.5.1
 Flask-Babel==1.0.0
 rsa==3.1.4
 flask-compress==1.15
+
+dataclasses==0.8
\ No newline at end of file