diff --git a/app/assets/javascripts/admin/components/site-setting.js.es6 b/app/assets/javascripts/admin/components/site-setting.js.es6
index 0289f4cdf4d..90c886c3a65 100644
--- a/app/assets/javascripts/admin/components/site-setting.js.es6
+++ b/app/assets/javascripts/admin/components/site-setting.js.es6
@@ -40,6 +40,10 @@ export default Component.extend(BufferedContent, SettingComponent, {
         "default_categories_tracking",
         "default_categories_muted",
         "default_categories_watching_first_post",
+        "default_tags_watching",
+        "default_tags_tracking",
+        "default_tags_muted",
+        "default_tags_watching_first_post",
         "default_text_size",
         "default_title_count_mode"
       ];
diff --git a/app/assets/javascripts/admin/components/site-settings/tag-list.js.es6 b/app/assets/javascripts/admin/components/site-settings/tag-list.js.es6
new file mode 100644
index 00000000000..417ad622cb8
--- /dev/null
+++ b/app/assets/javascripts/admin/components/site-settings/tag-list.js.es6
@@ -0,0 +1,15 @@
+import Component from "@ember/component";
+import computed from "ember-addons/ember-computed-decorators";
+
+export default Component.extend({
+  @computed("value")
+  selectedTags: {
+    get(value) {
+      return value.split("|");
+    },
+    set(value) {
+      this.set("value", value.join("|"));
+      return value;
+    }
+  }
+});
diff --git a/app/assets/javascripts/admin/mixins/setting-component.js.es6 b/app/assets/javascripts/admin/mixins/setting-component.js.es6
index 409c1b33595..3a7ab2e2c46 100644
--- a/app/assets/javascripts/admin/mixins/setting-component.js.es6
+++ b/app/assets/javascripts/admin/mixins/setting-component.js.es6
@@ -17,7 +17,8 @@ const CUSTOM_TYPES = [
   "compact_list",
   "secret_list",
   "upload",
-  "group_list"
+  "group_list",
+  "tag_list"
 ];
 
 const AUTO_REFRESH_ON_SAVE = ["logo", "logo_small", "large_icon"];
diff --git a/app/assets/javascripts/admin/templates/components/site-settings/tag-list.hbs b/app/assets/javascripts/admin/templates/components/site-settings/tag-list.hbs
new file mode 100644
index 00000000000..84c6623cfbb
--- /dev/null
+++ b/app/assets/javascripts/admin/templates/components/site-settings/tag-list.hbs
@@ -0,0 +1,3 @@
+{{tag-chooser tags=selectedTags}}
+<div class='desc'>{{{unbound setting.description}}}</div>
+{{setting-validation-message message=validationMessage}}
diff --git a/app/controllers/admin/site_settings_controller.rb b/app/controllers/admin/site_settings_controller.rb
index fdc6179187c..689b7bdc437 100644
--- a/app/controllers/admin/site_settings_controller.rb
+++ b/app/controllers/admin/site_settings_controller.rb
@@ -92,8 +92,35 @@ class Admin::SiteSettingsController < Admin::AdminController
             users.each { |user| category_users << { category_id: category_id, user_id: user.id, notification_level: notification_level } }
             CategoryUser.insert_all!(category_users)
           end
+        end
+      elsif id.start_with?("default_tags_")
+        previous_tag_ids = Tag.where(name: previous_value.split("|")).pluck(:id)
+        new_tag_ids = Tag.where(name: new_value.split("|")).pluck(:id)
+        now = Time.zone.now
 
-          CategoryUser.where(category_id: category_id, notification_level: notification_level).first_or_create!(notification_level: notification_level)
+        case id
+        when "default_tags_watching"
+          notification_level = NotificationLevels.all[:watching]
+        when "default_tags_tracking"
+          notification_level = NotificationLevels.all[:tracking]
+        when "default_tags_muted"
+          notification_level = NotificationLevels.all[:muted]
+        when "default_tags_watching_first_post"
+          notification_level = NotificationLevels.all[:watching_first_post]
+        end
+
+        (previous_tag_ids - new_tag_ids).each do |tag_id|
+          TagUser.where(tag_id: tag_id, notification_level: notification_level).delete_all
+        end
+
+        (new_tag_ids - previous_tag_ids).each do |tag_id|
+          skip_user_ids = TagUser.where(tag_id: tag_id).pluck(:user_id)
+
+          User.where.not(id: skip_user_ids).select(:id).find_in_batches do |users|
+            tag_users = []
+            users.each { |user| tag_users << { tag_id: tag_id, user_id: user.id, notification_level: notification_level, created_at: now, updated_at: now } }
+            TagUser.insert_all!(tag_users)
+          end
         end
       end
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index 0249ca5d0fa..aa5ac937a02 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -117,6 +117,7 @@ class User < ActiveRecord::Base
   after_create :set_random_avatar
   after_create :ensure_in_trust_level_group
   after_create :set_default_categories_preferences
+  after_create :set_default_tags_preferences
 
   after_update :trigger_user_updated_event, if: :saved_change_to_uploaded_avatar_id?
   after_update :trigger_user_automatic_group_refresh, if: :saved_change_to_staged?
@@ -1419,6 +1420,23 @@ class User < ActiveRecord::Base
     end
   end
 
+  def set_default_tags_preferences
+    return if self.staged?
+
+    values = []
+
+    %w{watching watching_first_post tracking muted}.each do |s|
+      tag_names = SiteSetting.get("default_tags_#{s}").split("|")
+      now = Time.zone.now
+
+      Tag.where(name: tag_names).pluck(:id).each do |tag_id|
+        values << { user_id: self.id, tag_id: tag_id, notification_level: TagUser.notification_levels[s.to_sym], created_at: now, updated_at: now }
+      end
+    end
+
+    TagUser.insert_all!(values) if values.present?
+  end
+
   def self.purge_unactivated
     return [] if SiteSetting.purge_unactivated_users_grace_period_days <= 0
 
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index b0aa5591066..c7e926513aa 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -198,6 +198,7 @@ en:
         one: "You specified the invalid choice %{name}"
         other: "You specified the invalid choices %{name}"
       default_categories_already_selected: "You cannot select a category used in another list."
+      default_tags_already_selected: "You cannot select a tag used in another list."
       s3_upload_bucket_is_required: "You cannot enable uploads to S3 unless you've provided the 's3_upload_bucket'."
       enable_s3_uploads_is_required: "You cannot enable inventory to S3 unless you've enabled the S3 uploads."
       s3_backup_requires_s3_settings: "You cannot use S3 as backup location unless you've provided the '%{setting_name}'."
@@ -2065,6 +2066,11 @@ en:
     default_categories_muted: "List of categories that are muted by default."
     default_categories_watching_first_post: "List of categories in which first post in each new topic will be watched by default."
 
+    default_tags_watching: "List of tags that are watched by default."
+    default_tags_tracking: "List of tags that are tracked by default."
+    default_tags_muted: "List of tags that are muted by default."
+    default_tags_watching_first_post: "List of tags in which first post in each new topic will be watched by default."
+
     default_text_size: "Text size which is selected by default"
 
     default_title_count_mode: "Default mode for the page title counter"
diff --git a/config/site_settings.yml b/config/site_settings.yml
index e6c1e167704..a70e811b79a 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -2023,6 +2023,19 @@ user_preferences:
     type: category_list
     default: ""
 
+  default_tags_watching:
+    type: tag_list
+    default: ""
+  default_tags_tracking:
+    type: tag_list
+    default: ""
+  default_tags_muted:
+    type: tag_list
+    default: ""
+  default_tags_watching_first_post:
+    type: tag_list
+    default: ""
+
   default_text_size:
     type: enum
     default: normal
diff --git a/lib/site_settings/type_supervisor.rb b/lib/site_settings/type_supervisor.rb
index 0f96b379086..420c64f60be 100644
--- a/lib/site_settings/type_supervisor.rb
+++ b/lib/site_settings/type_supervisor.rb
@@ -33,6 +33,7 @@ class SiteSettings::TypeSupervisor
       upload: 18,
       group: 19,
       group_list: 20,
+      tag_list: 21,
     )
   end
 
diff --git a/lib/site_settings/validations.rb b/lib/site_settings/validations.rb
index b8323e61213..be622022c7b 100644
--- a/lib/site_settings/validations.rb
+++ b/lib/site_settings/validations.rb
@@ -65,6 +65,58 @@ module SiteSettings::Validations
     validate_default_categories(category_ids, default_categories_selected)
   end
 
+  def validate_default_tags(tag_names, default_tags_selected)
+    validate_error :default_tags_already_selected if (tag_names & default_tags_selected).size > 0
+  end
+
+  def validate_default_tags_watching(new_val)
+    tag_names = new_val.split('|').to_set
+
+    default_tags_selected = [
+      SiteSetting.default_tags_tracking.split("|"),
+      SiteSetting.default_tags_muted.split("|"),
+      SiteSetting.default_tags_watching_first_post.split("|")
+    ].flatten.to_set
+
+    validate_default_tags(tag_names, default_tags_selected)
+  end
+
+  def validate_default_tags_tracking(new_val)
+    tag_names = new_val.split('|').to_set
+
+    default_tags_selected = [
+      SiteSetting.default_tags_watching.split("|"),
+      SiteSetting.default_tags_muted.split("|"),
+      SiteSetting.default_tags_watching_first_post.split("|")
+    ].flatten.to_set
+
+    validate_default_tags(tag_names, default_tags_selected)
+  end
+
+  def validate_default_tags_muted(new_val)
+    tag_names = new_val.split('|').to_set
+
+    default_tags_selected = [
+      SiteSetting.default_tags_watching.split("|"),
+      SiteSetting.default_tags_tracking.split("|"),
+      SiteSetting.default_tags_watching_first_post.split("|")
+    ].flatten.to_set
+
+    validate_default_tags(tag_names, default_tags_selected)
+  end
+
+  def validate_default_tags_watching_first_post(new_val)
+    tag_names = new_val.split('|').to_set
+
+    default_tags_selected = [
+      SiteSetting.default_tags_watching.split("|"),
+      SiteSetting.default_tags_tracking.split("|"),
+      SiteSetting.default_tags_muted.split("|")
+    ].flatten.to_set
+
+    validate_default_tags(tag_names, default_tags_selected)
+  end
+
   def validate_enable_s3_uploads(new_val)
     validate_error :s3_upload_bucket_is_required if new_val == "t" && SiteSetting.s3_upload_bucket.blank?
   end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 8055ad48a0e..567f94f6df8 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -159,6 +159,16 @@ describe User do
     end
   end
 
+  context '.set_default_tags_preferences' do
+    let(:tag) { Fabricate(:tag) }
+
+    it "should set default tag preferences when new user created" do
+      SiteSetting.default_tags_watching = tag.name
+      user = Fabricate(:user)
+      expect(TagUser.exists?(tag_id: tag.id, user_id: user.id, notification_level: TagUser.notification_levels[:watching])).to be_truthy
+    end
+  end
+
   describe 'reviewable' do
     let(:user) { Fabricate(:user, active: false) }
     fab!(:admin) { Fabricate(:admin) }
diff --git a/spec/requests/admin/site_settings_controller_spec.rb b/spec/requests/admin/site_settings_controller_spec.rb
index 7e035d7b7ae..166df37b40c 100644
--- a/spec/requests/admin/site_settings_controller_spec.rb
+++ b/spec/requests/admin/site_settings_controller_spec.rb
@@ -125,6 +125,44 @@ describe Admin::SiteSettingsController do
         end
       end
 
+      describe 'default tags' do
+        let(:user1) { Fabricate(:user) }
+        let(:user2) { Fabricate(:user) }
+        let(:watching) { NotificationLevels.all[:watching] }
+        let(:tracking) { NotificationLevels.all[:tracking] }
+
+        let(:tags) { 3.times.collect { Fabricate(:tag) } }
+
+        before do
+          SiteSetting.setting(:default_tags_watching, tags.first(2).pluck(:name).join("|"))
+          TagUser.create!(tag_id: tags.last.id, notification_level: tracking, user: user2)
+        end
+
+        after do
+          SiteSetting.setting(:default_tags_watching, "")
+        end
+
+        it 'should update existing users user preference' do
+          put "/admin/site_settings/default_tags_watching.json", params: {
+            default_tags_watching: tags.last(2).pluck(:name).join("|"),
+            updateExistingUsers: true
+          }
+
+          expect(TagUser.where(tag_id: tags.first.id, notification_level: watching).count).to eq(0)
+          expect(TagUser.where(tag_id: tags.last.id, notification_level: watching).count).to eq(User.count - 1)
+        end
+
+        it 'should not update existing users user preference' do
+          expect {
+            put "/admin/site_settings/default_tags_watching.json", params: {
+              default_tags_watching: tags.last(2).pluck(:name).join("|")
+            }
+          }.to change { TagUser.where(tag_id: tags.first.id, notification_level: watching).count }.by(0)
+
+          expect(TagUser.where(tag_id: tags.last.id, notification_level: watching).count).to eq(0)
+        end
+      end
+
       describe 'upload site settings' do
         it 'can remove the site setting' do
           SiteSetting.test_upload = Fabricate(:upload)