diff --git a/common/locales/en/quests.json b/common/locales/en/quests.json
index 7b3fe7af43..5edae258e5 100644
--- a/common/locales/en/quests.json
+++ b/common/locales/en/quests.json
@@ -78,5 +78,6 @@
     "whichQuestStart": "Which quest do you want to start?",
     "getMoreQuests": "Get more quests",
     "unlockedAQuest": "You unlocked a quest!",
-    "leveledUpReceivedQuest": "You leveled up to <strong>Level <%= level %></strong> and received a quest scroll!"
+    "leveledUpReceivedQuest": "You leveled up to <strong>Level <%= level %></strong> and received a quest scroll!",
+    "questInvitationDoesNotExist": "No quest invitation has been sent out yet."
 }
diff --git a/test/api/v3/integration/quests/POST-groups_groupid_quests_reject.test.js b/test/api/v3/integration/quests/POST-groups_groupid_quests_reject.test.js
new file mode 100644
index 0000000000..a222778948
--- /dev/null
+++ b/test/api/v3/integration/quests/POST-groups_groupid_quests_reject.test.js
@@ -0,0 +1,72 @@
+import {
+  createAndPopulateGroup,
+  translate as t,
+} from '../../../../helpers/api-v3-integration.helper';
+import { v4 as generateUUID } from 'uuid';
+
+describe('POST /groups/:groupId/quests/invite/:questKey', () => {
+  let questingGroup;
+  let member;
+  const PET_QUEST = 'whale';
+  let userQuestUpdate = {
+    items: {
+      quests: {},
+    },
+    'party.quest.RSVPNeeded': true,
+    'party.quest.key': PET_QUEST,
+  };
+
+  before(async () => {
+    let { group, members } = await createAndPopulateGroup({
+      groupDetails: { type: 'party', privacy: 'private' },
+      members: 1,
+    });
+
+    questingGroup = group;
+    member = members[0];
+
+    userQuestUpdate.items.quests[PET_QUEST] = 1;
+  });
+
+  context('failure conditions', () => {
+    it('returns an error when group is not found', async () => {
+      await expect(member.post(`/groups/${generateUUID()}/quests/reject`))
+        .to.eventually.be.rejected.and.eql({
+          code: 404,
+          error: 'NotFound',
+          message: t('groupNotFound'),
+        });
+    });
+
+    it('returns an error when group is not on a quest', async () => {
+      await member.update(userQuestUpdate);
+
+      await expect(member.post(`/groups/${questingGroup._id}/quests/reject`))
+        .to.eventually.be.rejected.and.eql({
+          code: 404,
+          error: 'NotFound',
+          message: t('questInvitationDoesNotExist'),
+        });
+    });
+  });
+
+  context('successfully quest rejection', () => {
+    it('rejects a quest invitation', async () => {
+      await member.update(userQuestUpdate);
+      await questingGroup.update({'quest.key': PET_QUEST});
+
+      let questMembers = {};
+      questMembers[member._id] = true;
+      await questingGroup.update({'quest.members': questMembers});
+
+      let rejectResult = await member.post(`/groups/${questingGroup._id}/quests/reject`);
+      let userWithRejectInvitation = await member.get('/user');
+      let updatedGroup = await member.get(`/groups/${questingGroup._id}`);
+
+      expect(userWithRejectInvitation.party.quest.key).to.be.null;
+      expect(userWithRejectInvitation.party.quest.RSVPNeeded).to.be.false;
+      expect(updatedGroup.quest.members[member._id]).to.be.false;
+      expect(updatedGroup.quest).to.deep.equal(rejectResult);
+    });
+  });
+});
diff --git a/website/src/controllers/api-v3/quests.js b/website/src/controllers/api-v3/quests.js
index 162954b7dd..0f1f991b7b 100644
--- a/website/src/controllers/api-v3/quests.js
+++ b/website/src/controllers/api-v3/quests.js
@@ -19,6 +19,8 @@ import {
   sendTxn as sendTxnEmail,
 } from '../../libs/api-v3/email';
 import { quests as questScrolls } from '../../../../common/script/content';
+import { track } from '../../libs/api-v3/analyticsService';
+import Q from 'q';
 
 function canStartQuestAutomatically (group)  {
   // If all members are either true (accepted) or false (rejected) return true
@@ -182,4 +184,58 @@ api.acceptQuest = {
   },
 };
 
+/**
+ * @api {post} /groups/:groupId/quests/reject Reject a quest
+ * @apiVersion 3.0.0
+ * @apiName RejectQuest
+ * @apiGroup Group
+ *
+ * @apiParam {string} groupId The group _id (or 'party')
+ * @apiParam {string} questKey The quest _id
+ *
+ * @apiSuccess {Object} Quest Object
+ */
+api.rejectQuest = {
+  method: 'POST',
+  url: '/groups/:groupId/quests/reject',
+  middlewares: [authWithHeaders(), cron],
+  async handler (req, res) {
+    let user = res.locals.user;
+
+    req.checkParams('groupId', res.t('groupIdRequired')).notEmpty();
+
+    let validationErrors = req.validationErrors();
+    if (validationErrors) throw validationErrors;
+
+    let group = await Group.getGroup({user, groupId: req.params.groupId, fields: 'type quest'});
+    if (!group) throw new NotFound(res.t('groupNotFound'));
+    if (!group.quest.key) throw new NotFound(res.t('questInvitationDoesNotExist'));
+
+    let analyticsData = {
+      category: 'behavior',
+      owner: false,
+      response: 'reject',
+      gaLabel: 'reject',
+      questName: group.quest.key,
+      uuid: user._id,
+    };
+    track('quest', analyticsData);
+
+    group.quest.members[user._id] = false;
+    group.markModified('quest.members');
+
+    user.party.quest.RSVPNeeded = false;
+    user.party.quest.key = null;
+
+    let [savedGroup] = await Q.all([
+      group.save(),
+      user.save(),
+    ]);
+
+    // questStart(req,res,next);
+
+    res.respond(200, savedGroup.quest);
+  },
+};
+
 export default api;