diff --git a/website/server/controllers/api-v3/members.js b/website/server/controllers/api-v3/members.js
index 11469a56847..93e2173bca0 100644
--- a/website/server/controllers/api-v3/members.js
+++ b/website/server/controllers/api-v3/members.js
@@ -27,6 +27,7 @@ import {
 } from '../../models/message';
 import highlightMentions from '../../libs/highlightMentions';
 import { handleGetMembersForChallenge } from '../../libs/challenges/handleGetMembersForChallenge';
+import { chatReporterFactory } from '../../libs/chatReporting/chatReporterFactory';
 
 const { achievements } = common;
 
@@ -777,4 +778,39 @@ api.transferGems = {
   },
 };
 
+/**
+ * @api {post} /api/v3/members/:memberId/flag Flag (report) a user
+ * @apiDescription Sends an email to staff about another user or their profile
+ * @apiName FlagUser
+ * @apiGroup Members
+ *
+ * @apiParam (Path) {UUID} memberId The unique ID of the user being flagged
+ * @apiParam (Body) {String} [comment] explain why the user was flagged
+ *
+ * @apiSuccess {Object} data The flagged user
+ * @apiSuccess {UUID} data.id The id of the flagged user
+ * @apiSuccess {String} data.username The username of the flagged user
+ * @apiSuccess {Object} data.profile The flagged user's profile information
+ * @apiSuccess {String} data.profile.blurb Text of the flagged user's profile bio
+ * @apiSuccess {String} data.profile.imageUrl URL of the flagged user's profile image
+ * @apiSuccess {String} data.profile.name The flagged user's display name
+ *
+ * @apiError (400) {BadRequest} AlreadyFlagged A profile cannot be flagged
+ *                                             more than once by the same user.
+ * @apiError (400) {BadRequest} MemberIdRequired The `memberId` param is required
+ *                                               and must be a valid `UUID`.
+ * @apiError (404) {NotFound} UserWithIdNotFound The `memberId` param did not
+ *                                               belong to an existing user.
+ */
+api.flagUser = {
+  method: 'POST',
+  url: '/members/:memberId/flag',
+  middlewares: [authWithHeaders()],
+  async handler (req, res) {
+    const chatReporter = chatReporterFactory('User', req, res);
+    const flaggedUser = await chatReporter.flag();
+    res.respond(200, flaggedUser);
+  },
+};
+
 export default api;
diff --git a/website/server/libs/chatReporting/chatReporterFactory.js b/website/server/libs/chatReporting/chatReporterFactory.js
index 39f8810ba54..e0b9e7b0196 100644
--- a/website/server/libs/chatReporting/chatReporterFactory.js
+++ b/website/server/libs/chatReporting/chatReporterFactory.js
@@ -1,11 +1,14 @@
 import GroupChatReporter from './groupChatReporter';
 import InboxChatReporter from './inboxChatReporter';
+import ProfileReporter from './profileReporter';
 
 export function chatReporterFactory (type, req, res) { // eslint-disable-line import/prefer-default-export, max-len
   if (type === 'Group') {
     return new GroupChatReporter(req, res);
   } if (type === 'Inbox') {
     return new InboxChatReporter(req, res);
+  } if (type === 'Profile' || type === 'User') {
+    return new ProfileReporter(req, res);
   }
 
   throw new Error('Invalid chat reporter type.');
diff --git a/website/server/libs/chatReporting/profileReporter.js b/website/server/libs/chatReporting/profileReporter.js
index 60a32899226..7374e249132 100644
--- a/website/server/libs/chatReporting/profileReporter.js
+++ b/website/server/libs/chatReporting/profileReporter.js
@@ -34,7 +34,8 @@ export default class ProfileReporter extends ChatReporter {
       throw new NotFound(this.res.t('userWithIDNotFound'));
     }
 
-    if (flaggedUser.profile.flags.indexOf(this.user._id) !== -1 && !this.user.hasPermission('moderator')) {
+    if (flaggedUser.profile.flags && flaggedUser.profile.flags.indexOf(this.user._id) !== -1
+      && !this.user.hasPermission('moderator')) {
       throw new BadRequest('A profile can not be flagged more than once by the same user.');
     }
 
@@ -64,6 +65,17 @@ export default class ProfileReporter extends ChatReporter {
     ];
   }
 
+  flagProfile (flaggedUser) {
+    // Log user ids that have flagged the account
+    if (!flaggedUser.profile.flags) {
+      flaggedUser.profile.flags = [];
+    }
+
+    flaggedUser.profile.flags.push(this.user._id);
+
+    return flaggedUser.save();
+  }
+
   async notify (flaggedUser, userComment) {
     let emailVariables = await this.getEmailVariables(flaggedUser);
     emailVariables = emailVariables.concat([
@@ -78,4 +90,14 @@ export default class ProfileReporter extends ChatReporter {
       userComment,
     });
   }
+
+  async flag () {
+    const { flaggedUser, userComment } = await this.validate();
+    await this.flagProfile(flaggedUser);
+    await this.notify(flaggedUser, userComment);
+    if (!this.user.hasPermission('moderator')) {
+      flaggedUser.profile.flags = [this.user._id];
+    }
+    return flaggedUser;
+  }
 }
\ No newline at end of file
diff --git a/website/server/libs/slack.js b/website/server/libs/slack.js
index 615c7d4284d..71dd0192177 100644
--- a/website/server/libs/slack.js
+++ b/website/server/libs/slack.js
@@ -176,6 +176,39 @@ function sendInboxFlagNotification ({
     .catch(err => logger.error(err, 'Error while sending flag data to Slack.'));
 }
 
+function sendProfileFlagNotification ({
+  reporter,
+  flaggedUser,
+  userComment,
+}) {
+  const title = 'User Profile Report';
+  const titleLink = `${BASE_URL}/static/front/#?memberId=${flaggedUser._id}`;
+  const text = `@${reporter.auth.local.username} (${reporter._id}; language: ${reporter.preferences.language}) flagged @${flaggedUser.auth.local.username}'s profile`;
+  if (userComment) {
+    text += ` and commented: ${userComment}`;
+  }
+  const profileData = `Bio: ${flaggedUser.profile.blurb}`;
+  if (flaggedUser.profile.imageUrl) {
+    profileData += `\n\nImage URL: ${flaggedUser.profile.imageUrl}`;
+  }
+
+  flagSlack
+    .send({
+      text,
+      attachments: [{
+        fallback: 'Flag Profile',
+        color: 'danger',
+        title,
+        title_link: titleLink,
+        text: profileData,
+        mrkdwn_in: [
+          'text',
+        ],
+      }],
+    })
+    .catch(err => logger.error(err, 'Error while sending flag data to Slack.'));
+}
+
 function sendSubscriptionNotification ({
   buyer,
   recipient,
@@ -302,6 +335,7 @@ function sendSlurNotification ({
 export {
   sendFlagNotification,
   sendInboxFlagNotification,
+  sendProfileFlagNotification,
   sendSubscriptionNotification,
   sendShadowMutedPostNotification,
   sendSlurNotification,
diff --git a/website/server/models/user/schema.js b/website/server/models/user/schema.js
index 8a98ee17ce2..ad5b7a11659 100644
--- a/website/server/models/user/schema.js
+++ b/website/server/models/user/schema.js
@@ -621,6 +621,9 @@ export default new Schema({
       required: true,
       trim: true,
     },
+    flags: [
+      { $type: String, validate: [v => validator.isUUID(v), 'Invalid user UUID.'], ref: 'User' },
+    ],
   },
   stats: {
     hp: { $type: Number, default: shared.maxHealth },