diff --git a/app/assets/javascripts/discourse/app/components/sidebar/tags-section.js b/app/assets/javascripts/discourse/app/components/sidebar/tags-section.js
index f2722244c4f..55dc9a376e5 100644
--- a/app/assets/javascripts/discourse/app/components/sidebar/tags-section.js
+++ b/app/assets/javascripts/discourse/app/components/sidebar/tags-section.js
@@ -1,15 +1,17 @@
 import I18n from "I18n";
 
 import { cached } from "@glimmer/tracking";
+import Component from "@glimmer/component";
 import { inject as service } from "@ember/service";
 import { action } from "@ember/object";
 
-import Component from "@glimmer/component";
 import TagSectionLink from "discourse/lib/sidebar/tags-section/tag-section-link";
+import PMTagSectionLink from "discourse/lib/sidebar/tags-section/pm-tag-section-link";
 
 export default class SidebarTagsSection extends Component {
   @service router;
   @service topicTrackingState;
+  @service pmTopicTrackingState;
   @service currentUser;
 
   constructor() {
@@ -17,7 +19,9 @@ export default class SidebarTagsSection extends Component {
 
     this.callbackId = this.topicTrackingState.onStateChange(() => {
       this.sectionLinks.forEach((sectionLink) => {
-        sectionLink.refreshCounts();
+        if (sectionLink.refreshCounts) {
+          sectionLink.refreshCounts();
+        }
       });
     });
   }
@@ -30,13 +34,22 @@ export default class SidebarTagsSection extends Component {
   get sectionLinks() {
     const links = [];
 
-    for (const tagName of this.currentUser.sidebarTagNames) {
-      links.push(
-        new TagSectionLink({
-          tagName,
-          topicTrackingState: this.topicTrackingState,
-        })
-      );
+    for (const tag of this.currentUser.sidebarTags) {
+      if (tag.pm_only) {
+        links.push(
+          new PMTagSectionLink({
+            tag,
+            currentUser: this.currentUser,
+          })
+        );
+      } else {
+        links.push(
+          new TagSectionLink({
+            tag,
+            topicTrackingState: this.topicTrackingState,
+          })
+        );
+      }
     }
 
     return links;
diff --git a/app/assets/javascripts/discourse/app/controllers/preferences/sidebar.js b/app/assets/javascripts/discourse/app/controllers/preferences/sidebar.js
index 73c840b008a..2b712f0290e 100644
--- a/app/assets/javascripts/discourse/app/controllers/preferences/sidebar.js
+++ b/app/assets/javascripts/discourse/app/controllers/preferences/sidebar.js
@@ -12,24 +12,29 @@ export default class extends Controller {
   @action
   save() {
     const initialSidebarCategoryIds = this.model.sidebarCategoryIds;
-    const initialSidebarTagNames = this.model.sidebarTagNames;
-
-    this.model.set("sidebar_tag_names", this.selectedSidebarTagNames);
 
     this.model.set(
       "sidebarCategoryIds",
       this.selectedSidebarCategories.mapBy("id")
     );
 
+    this.model.set("sidebar_tag_names", this.selectedSidebarTagNames);
+
     this.model
       .save()
-      .then(() => {
+      .then((result) => {
+        if (result.user.sidebar_tags) {
+          this.model.set("sidebar_tags", result.user.sidebar_tags);
+        }
+
         this.saved = true;
       })
       .catch((error) => {
         this.model.set("sidebarCategoryIds", initialSidebarCategoryIds);
-        this.model.set("sidebar_tag_names", initialSidebarTagNames);
         popupAjaxError(error);
+      })
+      .finally(() => {
+        this.model.set("sidebar_tag_names", []);
       });
   }
 }
diff --git a/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/pm-tag-section-link.js b/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/pm-tag-section-link.js
new file mode 100644
index 00000000000..aec926b6013
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/pm-tag-section-link.js
@@ -0,0 +1,22 @@
+export default class PMTagSectionLink {
+  constructor({ tag, currentUser }) {
+    this.tag = tag;
+    this.currentUser = currentUser;
+  }
+
+  get name() {
+    return this.tag.name;
+  }
+
+  get models() {
+    return [this.currentUser, this.tag.name];
+  }
+
+  get route() {
+    return "userPrivateMessages.tagsShow";
+  }
+
+  get text() {
+    return this.tag.name;
+  }
+}
diff --git a/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/tag-section-link.js b/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/tag-section-link.js
index fda4b8fa290..dd24165a494 100644
--- a/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/tag-section-link.js
+++ b/app/assets/javascripts/discourse/app/lib/sidebar/tags-section/tag-section-link.js
@@ -8,8 +8,8 @@ export default class TagSectionLink {
   @tracked totalUnread = 0;
   @tracked totalNew = 0;
 
-  constructor({ tagName, topicTrackingState }) {
-    this.tagName = tagName;
+  constructor({ tag, topicTrackingState }) {
+    this.tagName = tag.name;
     this.topicTrackingState = topicTrackingState;
     this.refreshCounts();
   }
@@ -31,18 +31,24 @@ export default class TagSectionLink {
     return this.tagName;
   }
 
-  get model() {
-    return this.tagName;
+  get models() {
+    return [this.tagName];
+  }
+
+  get route() {
+    if (this.totalUnread > 0) {
+      return "tag.showUnread";
+    } else if (this.totalNew > 0) {
+      return "tag.showNew";
+    } else {
+      return "tag.show";
+    }
   }
 
   get currentWhen() {
     return "tag.show tag.showNew tag.showUnread tag.showTop";
   }
 
-  get route() {
-    return "tag.show";
-  }
-
   get text() {
     return this.tagName;
   }
@@ -58,14 +64,4 @@ export default class TagSectionLink {
       });
     }
   }
-
-  get route() {
-    if (this.totalUnread > 0) {
-      return "tag.showUnread";
-    } else if (this.totalNew > 0) {
-      return "tag.showNew";
-    } else {
-      return "tag.show";
-    }
-  }
 }
diff --git a/app/assets/javascripts/discourse/app/models/user.js b/app/assets/javascripts/discourse/app/models/user.js
index 99e9eb4d8ca..76c4d828697 100644
--- a/app/assets/javascripts/discourse/app/models/user.js
+++ b/app/assets/javascripts/discourse/app/models/user.js
@@ -1,7 +1,7 @@
 import EmberObject, { computed, get, getProperties } from "@ember/object";
 import cookie, { removeCookie } from "discourse/lib/cookie";
 import { defaultHomepage, escapeExpression } from "discourse/lib/utilities";
-import { alias, equal, filterBy, gt, or } from "@ember/object/computed";
+import { alias, equal, filterBy, gt, mapBy, or } from "@ember/object/computed";
 import getURL, { getURLWithCDN } from "discourse-common/lib/get-url";
 import { A } from "@ember/array";
 import Badge from "discourse/models/badge";
@@ -314,15 +314,23 @@ const User = RestModel.extend({
 
   sidebarCategoryIds: alias("sidebar_category_ids"),
 
-  @discourseComputed("sidebar_tag_names.[]")
-  sidebarTagNames(sidebarTagNames) {
-    if (!sidebarTagNames || sidebarTagNames.length === 0) {
+  @discourseComputed("sidebar_tags.[]")
+  sidebarTags(sidebarTags) {
+    if (!sidebarTags || sidebarTags.length === 0) {
       return [];
     }
 
-    return sidebarTagNames;
+    if (this.siteSettings.tags_sort_alphabetically) {
+      return sidebarTags.sort((a, b) => {
+        return a.name.localeCompare(b);
+      });
+    } else {
+      return sidebarTags;
+    }
   },
 
+  sidebarTagNames: mapBy("sidebarTags", "name"),
+
   @discourseComputed("sidebar_category_ids.[]")
   sidebarCategories(sidebarCategoryIds) {
     if (!sidebarCategoryIds || sidebarCategoryIds.length === 0) {
@@ -446,6 +454,7 @@ const User = RestModel.extend({
         );
         User.current().setProperties(userProps);
         this.setProperties(updatedState);
+        return result;
       })
       .finally(() => {
         this.set("isSaving", false);
diff --git a/app/assets/javascripts/discourse/app/templates/components/sidebar/tags-section.hbs b/app/assets/javascripts/discourse/app/templates/components/sidebar/tags-section.hbs
index 1f94d16fc82..5e9e4193897 100644
--- a/app/assets/javascripts/discourse/app/templates/components/sidebar/tags-section.hbs
+++ b/app/assets/javascripts/discourse/app/templates/components/sidebar/tags-section.hbs
@@ -16,7 +16,7 @@
         @content={{sectionLink.text}}
         @currentWhen={{sectionLink.currentWhen}}
         @badgeText={{sectionLink.badgeText}}
-        @model={{sectionLink.model}}>
+        @models={{sectionLink.models}} >
       </Sidebar::SectionLink>
     {{/each}}
   {{else}}
diff --git a/app/assets/javascripts/discourse/tests/acceptance/sidebar-categories-section-test.js b/app/assets/javascripts/discourse/tests/acceptance/sidebar-categories-section-test.js
index 7abc849dbb1..9c7c2390b1a 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/sidebar-categories-section-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/sidebar-categories-section-test.js
@@ -57,7 +57,7 @@ acceptance(
 acceptance("Sidebar - Categories Section", function (needs) {
   needs.user({
     sidebar_category_ids: [],
-    sidebar_tag_names: [],
+    sidebar_tags: [],
   });
 
   needs.settings({
diff --git a/app/assets/javascripts/discourse/tests/acceptance/sidebar-tags-section-test.js b/app/assets/javascripts/discourse/tests/acceptance/sidebar-tags-section-test.js
index 4d370ea55af..c70e71b0f47 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/sidebar-tags-section-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/sidebar-tags-section-test.js
@@ -42,7 +42,18 @@ acceptance("Sidebar - Tags section", function (needs) {
     tracked_tags: ["tag1"],
     watched_tags: ["tag2", "tag3"],
     watching_first_post_tags: [],
-    sidebar_tag_names: ["tag1", "tag2", "tag3"],
+    sidebar_tags: [
+      { name: "tag1", pm_only: false },
+      { name: "tag2", pm_only: false },
+      {
+        name: "tag3",
+        pm_only: false,
+      },
+      {
+        name: "tag4",
+        pm_only: true,
+      },
+    ],
   });
 
   needs.pretender((server, helper) => {
@@ -52,6 +63,20 @@ acceptance("Sidebar - Tags section", function (needs) {
       });
     });
 
+    server.get("/topics/private-messages-tags/:username/:tagId", () => {
+      const topics = [
+        { id: 1, posters: [] },
+        { id: 2, posters: [] },
+        { id: 3, posters: [] },
+      ];
+
+      return helper.response({
+        topic_list: {
+          topics,
+        },
+      });
+    });
+
     ["latest", "top", "new", "unread"].forEach((type) => {
       server.get(`/tag/:tagId/l/${type}.json`, () => {
         return helper.response(
@@ -85,7 +110,7 @@ acceptance("Sidebar - Tags section", function (needs) {
 
   test("section content when user has not added any tags", async function (assert) {
     updateCurrentUser({
-      sidebar_tag_names: [],
+      sidebar_tags: [],
     });
 
     await visit("/");
@@ -106,8 +131,8 @@ acceptance("Sidebar - Tags section", function (needs) {
 
     assert.strictEqual(
       count(".sidebar-section-tags .sidebar-section-link"),
-      3,
-      "3 section links under the section"
+      4,
+      "4 section links under the section"
     );
 
     assert.strictEqual(
@@ -167,6 +192,29 @@ acceptance("Sidebar - Tags section", function (needs) {
     );
   });
 
+  test("private message tag section links for user", async function (assert) {
+    await visit("/");
+
+    await click(".sidebar-section-link-tag4");
+
+    assert.strictEqual(
+      currentURL(),
+      "/u/eviltrout/messages/tags/tag4",
+      "it should transition to user's private message tag4 tag page"
+    );
+
+    assert.strictEqual(
+      count(".sidebar-section-tags .sidebar-section-link.active"),
+      1,
+      "only one link is marked as active"
+    );
+
+    assert.ok(
+      exists(`.sidebar-section-link-tag4.active`),
+      "the tag4 section link is marked as active"
+    );
+  });
+
   test("visiting tag discovery top route", async function (assert) {
     await visit(`/tag/tag1/l/top`);
 
diff --git a/app/assets/javascripts/discourse/tests/acceptance/user-preferences-sidebar-test.js b/app/assets/javascripts/discourse/tests/acceptance/user-preferences-sidebar-test.js
index 6a2d3d429e8..c5c2b3aeb4c 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/user-preferences-sidebar-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/user-preferences-sidebar-test.js
@@ -12,7 +12,7 @@ import selectKit from "discourse/tests/helpers/select-kit-helper";
 acceptance("User Preferences - Sidebar", function (needs) {
   needs.user({
     sidebar_category_ids: [],
-    sidebar_tag_names: [],
+    sidebar_tags: [],
   });
 
   needs.settings({
@@ -39,7 +39,14 @@ acceptance("User Preferences - Sidebar", function (needs) {
         // This request format will cause an error
         return helper.response(400, {});
       } else {
-        return helper.response({ user: {} });
+        return helper.response({
+          user: {
+            sidebar_tags: [
+              { name: "monkey", pm_only: false },
+              { name: "gazelle", pm_only: false },
+            ],
+          },
+        });
       }
     });
   });
@@ -121,7 +128,7 @@ acceptance("User Preferences - Sidebar", function (needs) {
   });
 
   test("user encountering error when adding tags to sidebar", async function (assert) {
-    updateCurrentUser({ sidebar_tag_names: ["monkey"] });
+    updateCurrentUser({ sidebar_tags: [{ name: "monkey", pm_only: false }] });
 
     await visit("/");
 
diff --git a/app/serializers/concerns/user_sidebar_tags_mixin.rb b/app/serializers/concerns/user_sidebar_tags_mixin.rb
new file mode 100644
index 00000000000..f9ec79fbeea
--- /dev/null
+++ b/app/serializers/concerns/user_sidebar_tags_mixin.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module UserSidebarTagsMixin
+  def self.included(base)
+    base.has_many :sidebar_tags, serializer: Sidebar::TagSerializer, embed: :objects
+  end
+
+  def include_sidebar_tags?
+    SiteSetting.enable_experimental_sidebar_hamburger && SiteSetting.tagging_enabled
+  end
+end
diff --git a/app/serializers/current_user_serializer.rb b/app/serializers/current_user_serializer.rb
index a922e4fcaaa..cea7bda1857 100644
--- a/app/serializers/current_user_serializer.rb
+++ b/app/serializers/current_user_serializer.rb
@@ -2,6 +2,7 @@
 
 class CurrentUserSerializer < BasicUserSerializer
   include UserTagNotificationsMixin
+  include UserSidebarTagsMixin
 
   attributes :name,
              :unread_notifications,
@@ -75,7 +76,7 @@ class CurrentUserSerializer < BasicUserSerializer
              :pending_posts_count,
              :status,
              :sidebar_category_ids,
-             :sidebar_tag_names,
+             :sidebar_tags,
              :likes_notifications_disabled,
              :grouped_unread_high_priority_notifications,
              :redesigned_user_menu_enabled
@@ -315,14 +316,6 @@ class CurrentUserSerializer < BasicUserSerializer
     SiteSetting.enable_experimental_sidebar_hamburger
   end
 
-  def sidebar_tag_names
-    object.sidebar_tags.pluck(:name)
-  end
-
-  def include_sidebar_tag_names?
-    include_sidebar_category_ids? && SiteSetting.tagging_enabled
-  end
-
   def include_status?
     SiteSetting.enable_user_status && object.has_status?
   end
diff --git a/app/serializers/sidebar/tag_serializer.rb b/app/serializers/sidebar/tag_serializer.rb
new file mode 100644
index 00000000000..3e576cd2474
--- /dev/null
+++ b/app/serializers/sidebar/tag_serializer.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Sidebar
+  class TagSerializer < ::ApplicationSerializer
+    attributes :name, :pm_only
+
+    def pm_only
+      object.topic_count == 0 && object.pm_topic_count > 0
+    end
+  end
+end
diff --git a/app/serializers/user_card_serializer.rb b/app/serializers/user_card_serializer.rb
index 3170936174d..a109e9ebbfb 100644
--- a/app/serializers/user_card_serializer.rb
+++ b/app/serializers/user_card_serializer.rb
@@ -16,7 +16,11 @@ class UserCardSerializer < BasicUserSerializer
     attributes(*attrs)
     attrs.each do |attr|
       define_method "include_#{attr}?" do
-        can_edit
+        if defined?(super)
+          super() && can_edit
+        else
+          can_edit
+        end
       end
     end
   end
diff --git a/app/serializers/user_serializer.rb b/app/serializers/user_serializer.rb
index 7c0a97378c5..0e9f975032e 100644
--- a/app/serializers/user_serializer.rb
+++ b/app/serializers/user_serializer.rb
@@ -2,6 +2,7 @@
 
 class UserSerializer < UserCardSerializer
   include UserTagNotificationsMixin
+  include UserSidebarTagsMixin
 
   attributes :bio_raw,
              :bio_cooked,
@@ -62,7 +63,8 @@ class UserSerializer < UserCardSerializer
                      :user_api_keys,
                      :user_auth_tokens,
                      :user_notification_schedule,
-                     :use_logo_small_as_avatar
+                     :use_logo_small_as_avatar,
+                     :sidebar_tags
 
   untrusted_attributes :bio_raw,
                        :bio_cooked,
diff --git a/spec/serializers/current_user_serializer_spec.rb b/spec/serializers/current_user_serializer_spec.rb
index 7063db3fdce..85ede7e1344 100644
--- a/spec/serializers/current_user_serializer_spec.rb
+++ b/spec/serializers/current_user_serializer_spec.rb
@@ -220,45 +220,39 @@ RSpec.describe CurrentUserSerializer do
     end
   end
 
-  describe '#sidebar_tag_names' do
+  describe '#sidebar_tags' do
     fab!(:tag_sidebar_section_link) { Fabricate(:tag_sidebar_section_link, user: user) }
     fab!(:tag_sidebar_section_link_2) { Fabricate(:tag_sidebar_section_link, user: user) }
 
-    it "is not included when SiteSeting.enable_experimental_sidebar_hamburger is false" do
-      SiteSetting.enable_experimental_sidebar_hamburger = false
-
-      json = serializer.as_json
-
-      expect(json[:sidebar_tag_names]).to eq(nil)
-    end
-
-    it "is not included when SiteSeting.tagging_enabled is false" do
-      SiteSetting.enable_experimental_sidebar_hamburger = true
-      SiteSetting.tagging_enabled = false
-
-      json = serializer.as_json
-
-      expect(json[:sidebar_tag_names]).to eq(nil)
-    end
-
     it "is not included when experimental sidebar has not been enabled" do
       SiteSetting.enable_experimental_sidebar_hamburger = false
       SiteSetting.tagging_enabled = true
 
       json = serializer.as_json
 
-      expect(json[:sidebar_tag_names]).to eq(nil)
+      expect(json[:sidebar_tags]).to eq(nil)
     end
 
-    it "is present when experimental sidebar has been enabled" do
+    it "is not included when tagging has not been enabled" do
       SiteSetting.enable_experimental_sidebar_hamburger = true
-      SiteSetting.tagging_enabled = true
+      SiteSetting.tagging_enabled = false
 
       json = serializer.as_json
 
-      expect(json[:sidebar_tag_names]).to contain_exactly(
-        tag_sidebar_section_link.linkable.name,
-        tag_sidebar_section_link_2.linkable.name
+      expect(json[:sidebar_tags]).to eq(nil)
+    end
+
+    it "is present when experimental sidebar and tagging has been enabled" do
+      SiteSetting.enable_experimental_sidebar_hamburger = true
+      SiteSetting.tagging_enabled = true
+
+      tag_sidebar_section_link_2.linkable.update!(pm_topic_count: 5, topic_count: 0)
+
+      json = serializer.as_json
+
+      expect(json[:sidebar_tags]).to contain_exactly(
+        { name: tag_sidebar_section_link.linkable.name, pm_only: false },
+        { name: tag_sidebar_section_link_2.linkable.name, pm_only: true }
       )
     end
   end
diff --git a/spec/serializers/user_serializer_spec.rb b/spec/serializers/user_serializer_spec.rb
index bfe37e15bf0..966d5f225fb 100644
--- a/spec/serializers/user_serializer_spec.rb
+++ b/spec/serializers/user_serializer_spec.rb
@@ -376,4 +376,52 @@ RSpec.describe UserSerializer do
       expect(json[:user_api_keys][2][:id]).to eq(user_api_key_2.id)
     end
   end
+
+  describe '#sidebar_tags' do
+    fab!(:tag_sidebar_section_link) { Fabricate(:tag_sidebar_section_link, user: user) }
+    fab!(:tag_sidebar_section_link_2) { Fabricate(:tag_sidebar_section_link, user: user) }
+
+    context 'when viewing self' do
+      subject(:json) { UserSerializer.new(user, scope: Guardian.new(user), root: false).as_json }
+
+      it "is not included when SiteSeting.enable_experimental_sidebar_hamburger is false" do
+        SiteSetting.enable_experimental_sidebar_hamburger = false
+        SiteSetting.tagging_enabled = true
+
+        expect(json[:sidebar_tags]).to eq(nil)
+      end
+
+      it "is not included when SiteSeting.tagging_enabled is false" do
+        SiteSetting.enable_experimental_sidebar_hamburger = true
+        SiteSetting.tagging_enabled = false
+
+        expect(json[:sidebar_tags]).to eq(nil)
+      end
+
+      it "is present when experimental sidebar and tagging has been enabled" do
+        SiteSetting.enable_experimental_sidebar_hamburger = true
+        SiteSetting.tagging_enabled = true
+
+        tag_sidebar_section_link_2.linkable.update!(pm_topic_count: 5, topic_count: 0)
+
+        expect(json[:sidebar_tags]).to contain_exactly(
+          { name: tag_sidebar_section_link.linkable.name, pm_only: false },
+          { name: tag_sidebar_section_link_2.linkable.name, pm_only: true }
+        )
+      end
+    end
+
+    context 'when viewing another user' do
+      fab!(:user2) { Fabricate(:user) }
+
+      subject(:json) { UserSerializer.new(user, scope: Guardian.new(user2), root: false).as_json }
+
+      it "is not present even when experimental sidebar and tagging has been enabled" do
+        SiteSetting.enable_experimental_sidebar_hamburger = true
+        SiteSetting.tagging_enabled = true
+
+        expect(json[:sidebar_tags]).to eq(nil)
+      end
+    end
+  end
 end