diff --git a/CHANGELOG b/CHANGELOG
index b0adaeb101b..1d334edc904 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -9,6 +9,7 @@ v 7.9.0 (unreleased)
   - Fix merge request URL passed to Webhooks. (Stan Hu)
   - Fix bug that caused a server error when editing a comment to "+1" or "-1" (Stan Hu)
   - Fix code preview theme setting for comments, issues, merge requests, and snippets (Stan Hu)
+  - Add a service to support external wikis (Hannes Rosenögger)
   - Move labels/milestones tabs to sidebar
   - Upgrade Rails gem to version 4.1.9.
   - Improve error messages for file edit failures
diff --git a/app/controllers/projects/services_controller.rb b/app/controllers/projects/services_controller.rb
index 570447c746c..9a484c109ba 100644
--- a/app/controllers/projects/services_controller.rb
+++ b/app/controllers/projects/services_controller.rb
@@ -53,7 +53,7 @@ class Projects::ServicesController < Projects::ApplicationController
       :description, :issues_url, :new_issue_url, :restrict_to_branch, :channel,
       :colorize_messages, :channels,
       :push_events, :issues_events, :merge_requests_events, :tag_push_events,
-      :note_events, :send_from_committer_email, :disable_diffs
+      :note_events, :send_from_committer_email, :disable_diffs, :external_wiki_url
     )
   end
 end
diff --git a/app/helpers/external_wiki_helper.rb b/app/helpers/external_wiki_helper.rb
new file mode 100644
index 00000000000..838b85afdfe
--- /dev/null
+++ b/app/helpers/external_wiki_helper.rb
@@ -0,0 +1,11 @@
+module ExternalWikiHelper
+  def get_project_wiki_path(project)
+    external_wiki_service = project.services.
+      select { |service| service.to_param == 'external_wiki' }.first
+    if external_wiki_service.present? && external_wiki_service.active?
+      external_wiki_service.properties['external_wiki_url']
+    else
+      namespace_project_wiki_path(project.namespace, project, :home)
+    end
+  end
+end
diff --git a/app/models/project.rb b/app/models/project.rb
index c45338bf4eb..5fbda1ae86c 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -93,6 +93,7 @@ class Project < ActiveRecord::Base
   has_one :forked_project_link, dependent: :destroy, foreign_key: "forked_to_project_id"
 
   has_one :forked_from_project, through: :forked_project_link
+  has_one :external_wiki_service, dependent: :destroy
   # Merge Requests for target project should be removed with it
   has_many :merge_requests,     dependent: :destroy, foreign_key: 'target_project_id'
   # Merge requests from source project should be kept when source project was removed
diff --git a/app/models/project_services/external_wiki_service.rb b/app/models/project_services/external_wiki_service.rb
new file mode 100644
index 00000000000..e521186798c
--- /dev/null
+++ b/app/models/project_services/external_wiki_service.rb
@@ -0,0 +1,48 @@
+# == Schema Information
+#
+# Table name: services
+#
+#  id         :integer          not null, primary key
+#  type       :string(255)
+#  title      :string(255)
+#  project_id :integer          not null
+#  created_at :datetime
+#  updated_at :datetime
+#  active     :boolean          default(FALSE), not null
+#  properties :text
+#
+
+class ExternalWikiService < Service
+  include HTTParty
+
+  prop_accessor :external_wiki_url
+  validates :external_wiki_url,
+            presence: true,
+            format: { with: URI::regexp },
+            if: :activated?
+
+  def title
+    'External Wiki'
+  end
+
+  def description
+    'Replaces the link to the internal wiki with a link to an external wiki.'
+  end
+
+  def to_param
+    'external_wiki'
+  end
+
+  def fields
+    [
+      { type: 'text', name: 'external_wiki_url', placeholder: 'The URL of the external Wiki' },
+    ]
+  end
+
+  def execute(_data)
+    @response = HTTParty.get(properties['external_wiki_url'], verify: true) rescue nil
+    if @response !=200
+      nil
+    end
+  end
+end
diff --git a/app/views/layouts/nav/_project.html.haml b/app/views/layouts/nav/_project.html.haml
index d340ab1796a..91cae2b572c 100644
--- a/app/views/layouts/nav/_project.html.haml
+++ b/app/views/layouts/nav/_project.html.haml
@@ -75,7 +75,7 @@
 
     - if project_nav_tab? :wiki
       = nav_link(controller: :wikis) do
-        = link_to namespace_project_wiki_path(@project.namespace, @project, :home), title: 'Wiki', class: 'shortcuts-wiki' do
+        = link_to get_project_wiki_path(@project), title: 'Wiki', class: 'shortcuts-wiki' do
           %i.fa.fa-book
           %span
             Wiki
diff --git a/spec/models/external_wiki_service_spec.rb b/spec/models/external_wiki_service_spec.rb
new file mode 100644
index 00000000000..78ef687d29c
--- /dev/null
+++ b/spec/models/external_wiki_service_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+
+describe ExternalWikiService do
+  include ExternalWikiHelper
+  describe "Associations" do
+    it { should belong_to :project }
+    it { should have_one :service_hook }
+  end
+
+  describe "Validations" do
+    context "active" do
+      before do
+        subject.active = true
+      end
+
+      it { should validate_presence_of :external_wiki_url }
+    end
+  end
+
+  describe 'External wiki' do
+    let(:project) { create(:project) }
+
+    context 'when it is active' do
+      before do
+        properties = { 'external_wiki_url' => 'https://gitlab.com' }
+        @service = project.create_external_wiki_service(active: true, properties: properties)
+      end
+
+      after do
+        @service.destroy!
+      end
+
+      it 'should replace the wiki url' do
+        wiki_path = get_project_wiki_path(project)
+        wiki_path.should match('https://gitlab.com')
+      end
+    end
+  end
+end