diff --git a/app/assets/javascripts/discourse/app/components/composer-messages.js b/app/assets/javascripts/discourse/app/components/composer-messages.js
index a888c2829ca..ad323bcb55b 100644
--- a/app/assets/javascripts/discourse/app/components/composer-messages.js
+++ b/app/assets/javascripts/discourse/app/components/composer-messages.js
@@ -76,7 +76,7 @@ export default Component.extend({
 
     shareModal() {
       const { topic } = this.composer;
-      const controller = showModal("share-topic");
+      const controller = showModal("share-topic", { model: topic.category });
       controller.setProperties({
         allowInvites:
           topic.details.can_invite_to &&
diff --git a/app/assets/javascripts/discourse/app/controllers/share-topic.js b/app/assets/javascripts/discourse/app/controllers/share-topic.js
index 7f8d3e2a85f..d1c3657be02 100644
--- a/app/assets/javascripts/discourse/app/controllers/share-topic.js
+++ b/app/assets/javascripts/discourse/app/controllers/share-topic.js
@@ -9,13 +9,29 @@ import showModal from "discourse/lib/show-modal";
 import { bufferedProperty } from "discourse/mixins/buffered-content";
 import ModalFunctionality from "discourse/mixins/modal-functionality";
 import I18n from "I18n";
+import Category from "discourse/models/category";
 
 export default Controller.extend(
   ModalFunctionality,
   bufferedProperty("invite"),
   {
+    topic: null,
+    restrictedGroups: null,
+
     onShow() {
       this.set("showNotifyUsers", false);
+
+      if (this.model && this.model.read_restricted) {
+        Category.reloadBySlugPath(this.model.slug).then((result) => {
+          this.setProperties({
+            restrictedGroups: result.category.group_permissions.map(
+              (g) => g.group_name
+            ),
+          });
+        });
+      } else {
+        this.setProperties({ restrictedGroups: null });
+      }
     },
 
     @discourseComputed("topic.shareUrl")
@@ -39,6 +55,21 @@ export default Controller.extend(
       );
     },
 
+    @discourseComputed("restrictedGroups")
+    hasRestrictedGroups(groups) {
+      return !!groups;
+    },
+
+    @discourseComputed("restrictedGroups")
+    restrictedGroupsCount(groups) {
+      return groups.length;
+    },
+
+    @discourseComputed("restrictedGroups")
+    restrictedGroupsDisplayText(groups) {
+      return groups.join(", ");
+    },
+
     @action
     onChangeUsers(usernames) {
       this.set("users", usernames.uniq());
diff --git a/app/assets/javascripts/discourse/app/initializers/topic-footer-buttons.js b/app/assets/javascripts/discourse/app/initializers/topic-footer-buttons.js
index a8aa789b9c5..a5a52277718 100644
--- a/app/assets/javascripts/discourse/app/initializers/topic-footer-buttons.js
+++ b/app/assets/javascripts/discourse/app/initializers/topic-footer-buttons.js
@@ -23,7 +23,9 @@ export default {
       },
       title: "topic.share.help",
       action() {
-        const controller = showModal("share-topic");
+        const controller = showModal("share-topic", {
+          model: this.topic.category,
+        });
         controller.setProperties({
           allowInvites: this.canInviteTo && !this.inviteDisabled,
           topic: this.topic,
diff --git a/app/assets/javascripts/discourse/app/templates/modal/share-topic.hbs b/app/assets/javascripts/discourse/app/templates/modal/share-topic.hbs
index cbdac5666a3..ff2de507144 100644
--- a/app/assets/javascripts/discourse/app/templates/modal/share-topic.hbs
+++ b/app/assets/javascripts/discourse/app/templates/modal/share-topic.hbs
@@ -12,6 +12,13 @@
         {{copy-button selector="input.invite-link"}}
       </div>
     </div>
+
+    {{#if hasRestrictedGroups}}
+      <div class="link-share-restricted-groups">
+        {{i18n "topic.share.restricted_groups" count=restrictedGroupsCount}}
+        {{restrictedGroupsDisplayText}}
+      </div>
+    {{/if}}
     <div class="link-share-actions">
       <div class="sources">
         {{#each sources as |s|}}
diff --git a/app/assets/javascripts/discourse/tests/acceptance/share-topic-test.js b/app/assets/javascripts/discourse/tests/acceptance/share-topic-test.js
index 0b952d616d2..3446b53f2ab 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/share-topic-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/share-topic-test.js
@@ -48,6 +48,23 @@ acceptance("Share and Invite modal", function (needs) {
 
     assert.ok(exists("#share-link"), "it shows the share modal");
   });
+
+  test("Share topic in a restricted category", async function (assert) {
+    await visit("/t/topic-in-restricted-group/2481");
+
+    assert.ok(
+      exists("#topic-footer-button-share-and-invite"),
+      "the button exists"
+    );
+
+    await click("#topic-footer-button-share-and-invite");
+
+    assert.ok(exists(".share-topic-modal"), "it shows the modal");
+    assert.ok(
+      exists(".link-share-restricted-groups"),
+      "it shows restricted warning"
+    );
+  });
 });
 
 acceptance("Share and Invite modal - mobile", function (needs) {
diff --git a/app/assets/javascripts/discourse/tests/fixtures/category-fixtures.js b/app/assets/javascripts/discourse/tests/fixtures/category-fixtures.js
index 6edf9ea190b..44ed93de9fb 100644
--- a/app/assets/javascripts/discourse/tests/fixtures/category-fixtures.js
+++ b/app/assets/javascripts/discourse/tests/fixtures/category-fixtures.js
@@ -48,5 +48,18 @@ export default {
       slug: "testing",
       can_edit: true
     }
-  }
+  },
+  "/c/2481/show.json": {
+    category: {
+      id: 2481,
+      name: "restricted-group",
+      color: "e9dd00",
+      text_color: "000000",
+      slug: "restricted-group",
+      read_restricted: true,
+      permission: null,
+      group_permissions: [{ permission_type: 1, group_name: "moderators" }],
+    }
+  },
+
 };
diff --git a/app/assets/javascripts/discourse/tests/fixtures/site-fixtures.js b/app/assets/javascripts/discourse/tests/fixtures/site-fixtures.js
index 68488ba5f9e..1151e2e20aa 100644
--- a/app/assets/javascripts/discourse/tests/fixtures/site-fixtures.js
+++ b/app/assets/javascripts/discourse/tests/fixtures/site-fixtures.js
@@ -438,6 +438,23 @@ export default {
           default_view: "latest",
           subcategory_list_style: "boxes",
         },
+        {
+          id: 2481,
+          name: "Restricted Group",
+          color: "0E78BD",
+          text_color: "FFFFFF",
+          slug: "restricted-group",
+          topic_count: 137,
+          post_count: 1142,
+          description: "A restricted group",
+          topic_url: "/t/category-definition-for-restricted-group/11",
+          read_restricted: true,
+          permission: 1,
+          notification_level: null,
+          show_subcategory_list: true,
+          default_view: "latest",
+          subcategory_list_style: "boxes",
+        },
       ],
       post_action_types: [
         {
diff --git a/app/assets/javascripts/discourse/tests/fixtures/topic.js b/app/assets/javascripts/discourse/tests/fixtures/topic.js
index a4db6fe4977..35437dbca92 100644
--- a/app/assets/javascripts/discourse/tests/fixtures/topic.js
+++ b/app/assets/javascripts/discourse/tests/fixtures/topic.js
@@ -5855,4 +5855,347 @@ export default {
       },
     },
   },
+  "/t/2481/1.json": {
+    post_stream: {
+      posts: [
+        {
+          id: 2441,
+          name: "",
+          username: "group_moderator",
+          avatar_template: "/images/avatar.png",
+          created_at: "2020-07-24T17:48:55.419Z",
+          cooked:
+            "<p>Here is my new topic. I am a group category moderator!</p>",
+          post_number: 1,
+          post_type: 1,
+          updated_at: "2020-07-24T17:48:55.419Z",
+          reply_count: 0,
+          reply_to_post_number: null,
+          quote_count: 0,
+          incoming_link_count: 0,
+          reads: 2,
+          readers_count: 1,
+          score: 0,
+          yours: true,
+          topic_id: 2481,
+          topic_slug: "topic-in-restricted-group",
+          display_username: "",
+          primary_group_name: "group_moderators",
+          flair_name: "group_moderators",
+          flair_url: "cheese",
+          flair_bg_color: "ff0",
+          flair_color: "",
+          version: 1,
+          can_edit: true,
+          can_delete: false,
+          can_recover: false,
+          can_wiki: false,
+          read: true,
+          user_title: "a title",
+          title_is_group: false,
+          bookmarked: false,
+          bookmarks: [],
+          actions_summary: [
+            {
+              id: 3,
+              can_act: true,
+            },
+            {
+              id: 4,
+              can_act: true,
+            },
+            {
+              id: 8,
+              can_act: true,
+            },
+            {
+              id: 7,
+              can_act: true,
+            },
+          ],
+          moderator: false,
+          admin: false,
+          staff: false,
+          group_moderator: true,
+          user_id: 3,
+          hidden: false,
+          trust_level: 1,
+          deleted_at: null,
+          user_deleted: false,
+          edit_reason: null,
+          can_view_edit_history: true,
+          wiki: false,
+          reviewable_id: 0,
+          reviewable_score_count: 0,
+          reviewable_score_pending_count: 0,
+        },
+        {
+          id: 2442,
+          name: "",
+          username: "normal_user",
+          avatar_template: "/images/avatar.png",
+          created_at: "2020-07-24T17:50:01.263Z",
+          cooked: "<p>A fascinating topic worthy of discussion.</p>",
+          post_number: 2,
+          post_type: 1,
+          updated_at: "2020-07-24T17:50:01.263Z",
+          reply_count: 0,
+          reply_to_post_number: null,
+          quote_count: 0,
+          incoming_link_count: 0,
+          reads: 2,
+          readers_count: 1,
+          score: 0,
+          yours: false,
+          topic_id: 2481,
+          topic_slug: "topic-in-restricted-group",
+          display_username: "",
+          primary_group_name: null,
+          flair_name: null,
+          flair_url: null,
+          flair_bg_color: null,
+          flair_color: null,
+          version: 1,
+          can_edit: false,
+          can_delete: false,
+          can_recover: false,
+          can_wiki: false,
+          read: true,
+          user_title: null,
+          bookmarked: false,
+          bookmarks: [],
+          actions_summary: [
+            {
+              id: 2,
+              can_act: true,
+            },
+            {
+              id: 3,
+              can_act: true,
+            },
+            {
+              id: 4,
+              can_act: true,
+            },
+            {
+              id: 8,
+              can_act: true,
+            },
+            {
+              id: 6,
+              can_act: true,
+            },
+            {
+              id: 7,
+              can_act: true,
+            },
+          ],
+          moderator: false,
+          admin: false,
+          staff: false,
+          user_id: 2,
+          hidden: false,
+          trust_level: 1,
+          deleted_at: null,
+          user_deleted: false,
+          edit_reason: null,
+          can_view_edit_history: true,
+          wiki: false,
+          reviewable_id: 0,
+          reviewable_score_count: 0,
+          reviewable_score_pending_count: 0,
+        },
+        {
+          id: 2443,
+          name: "",
+          username: "group_moderator",
+          avatar_template: "/images/avatar.png",
+          created_at: "2020-07-24T17:50:17.274Z",
+          cooked: '<aside class="onebox allowlistedgeneric" data-onebox-src="https://example.com/57350945"><header class="source"><a href="https://example.com/57350945" target="_blank" rel="noopener">XYZ News Site</a> </header> <article class="onebox-body"> <div class="aspect-image" style="--aspect-ratio:690/388;"><img src="/assets/logo.png" class="thumbnail d-lazyload" width="690" height="388"></div> <h3><a href="https://example.com/57350945" target="_blank" rel="noopener">News Headline</a></h3> <p>Article summary</p> </article> <div class="onebox-metadata"> </div> <div style="clear: both"></div> </aside>',
+          post_number: 3,
+          post_type: 1,
+          updated_at: "2020-07-24T17:50:17.274Z",
+          reply_count: 0,
+          reply_to_post_number: null,
+          quote_count: 0,
+          incoming_link_count: 0,
+          reads: 2,
+          readers_count: 1,
+          score: 0,
+          yours: true,
+          topic_id: 2481,
+          topic_slug: "topic-in-restricted-group",
+          display_username: "",
+          primary_group_name: "group_moderators",
+          flair_url: "cheese",
+          flair_bg_color: "ff0",
+          flair_color: "",
+          version: 1,
+          can_edit: true,
+          can_delete: true,
+          can_recover: false,
+          can_wiki: false,
+          read: true,
+          user_title: "a title",
+          title_is_group: false,
+          bookmarked: false,
+          bookmarks: [],
+          actions_summary: [
+            {
+              id: 3,
+              can_act: true,
+            },
+            {
+              id: 4,
+              can_act: true,
+            },
+            {
+              id: 8,
+              can_act: true,
+            },
+            {
+              id: 7,
+              can_act: true,
+            },
+          ],
+          moderator: false,
+          admin: false,
+          staff: false,
+          group_moderator: true,
+          user_id: 3,
+          hidden: false,
+          trust_level: 1,
+          deleted_at: null,
+          user_deleted: false,
+          edit_reason: null,
+          can_view_edit_history: true,
+          wiki: false,
+          reviewable_id: 0,
+          reviewable_score_count: 0,
+          reviewable_score_pending_count: 0,
+        },
+      ],
+      stream: [2441, 2442, 2443],
+    },
+    timeline_lookup: [[1, 0]],
+    id: 2481,
+    title: "A Topic in a Restricted Group",
+    fancy_title: "A Topic in a Restricted Group",
+    posts_count: 3,
+    created_at: "2020-07-24T17:48:54.986Z",
+    views: 2,
+    reply_count: 0,
+    like_count: 0,
+    last_posted_at: "2020-07-24T17:50:17.274Z",
+    visible: true,
+    closed: false,
+    archived: false,
+    has_summary: false,
+    archetype: "regular",
+    slug: "topic-in-restricted-group",
+    category_id: 2481,
+    word_count: 22,
+    deleted_at: null,
+    user_id: 3,
+    featured_link: null,
+    pinned_globally: false,
+    pinned_at: null,
+    pinned_until: null,
+    image_url: null,
+    draft: null,
+    draft_key: "topic_2481",
+    draft_sequence: 1,
+    posted: true,
+    unpinned: null,
+    pinned: false,
+    current_post_number: 3,
+    highest_post_number: 3,
+    last_read_post_number: 3,
+    last_read_post_id: 43,
+    deleted_by: null,
+    actions_summary: [
+      {
+        id: 4,
+        count: 0,
+        hidden: false,
+        can_act: true,
+      },
+      {
+        id: 8,
+        count: 0,
+        hidden: false,
+        can_act: true,
+      },
+      {
+        id: 7,
+        count: 0,
+        hidden: false,
+        can_act: true,
+      },
+    ],
+    chunk_size: 20,
+    bookmarked: false,
+    bookmarks: [],
+    topic_timer: null,
+    message_bus_last_id: 4,
+    participant_count: 2,
+    show_read_indicator: false,
+    thumbnails: null,
+    details: {
+      notification_level: 3,
+      notifications_reason_id: 1,
+      can_delete: true,
+      can_edit: true,
+      can_create_post: true,
+      can_move_posts: true,
+      can_reply_as_new_topic: true,
+      can_flag_topic: true,
+      can_review_topic: true,
+      can_close_topic: true,
+      can_archive_topic: true,
+      can_toggle_topic_visibility: true,
+      can_split_merge_topic: true,
+      can_edit_staff_notes: true,
+      can_pin_unpin_topic: true,
+      can_moderate_category: true,
+      participants: [
+        {
+          id: 3,
+          username: "group_moderator",
+          name: "",
+          avatar_template: "/images/avatar.png",
+          post_count: 2,
+          primary_group_name: "group_moderators",
+          flar_name: "group_moderators",
+          flair_url: "cheese",
+          flair_color: "",
+          flair_bg_color: "ff0",
+        },
+        {
+          id: 2,
+          username: "normal_user",
+          name: "",
+          avatar_template: "/images/avatar.png",
+          post_count: 1,
+          primary_group_name: null,
+          flair_name: null,
+          flair_url: null,
+          flair_color: null,
+          flair_bg_color: null,
+        },
+      ],
+      created_by: {
+        id: 3,
+        username: "group_moderator",
+        name: "",
+        avatar_template: "/images/avatar.png",
+      },
+      last_poster: {
+        id: 3,
+        username: "group_moderator",
+        name: "",
+        avatar_template: "/images/avatar.png",
+      },
+    },
+  },
 };
diff --git a/app/assets/javascripts/discourse/tests/helpers/create-pretender.js b/app/assets/javascripts/discourse/tests/helpers/create-pretender.js
index a81481281ea..9301d6ddc24 100644
--- a/app/assets/javascripts/discourse/tests/helpers/create-pretender.js
+++ b/app/assets/javascripts/discourse/tests/helpers/create-pretender.js
@@ -281,6 +281,9 @@ export function applyDefaultHandlers(pretender) {
   pretender.get("/t/2480.json", () =>
     response(fixturesByUrl["/t/2480/1.json"])
   );
+  pretender.get("/t/2481.json", () =>
+    response(fixturesByUrl["/t/2481/1.json"])
+  );
 
   pretender.get("/t/id_for/:slug", () => {
     return response({
@@ -344,6 +347,10 @@ export function applyDefaultHandlers(pretender) {
     response(fixturesByUrl["/c/1/show.json"])
   );
 
+  pretender.get("/c/restricted-group/find_by_slug.json", () =>
+    response(fixturesByUrl["/c/2481/show.json"])
+  );
+
   pretender.put("/categories/:category_id", (request) => {
     const category = parsePostData(request.requestBody);
     category.id = parseInt(request.params.category_id, 10);
diff --git a/app/assets/javascripts/discourse/tests/integration/components/select-kit/category-chooser-test.js b/app/assets/javascripts/discourse/tests/integration/components/select-kit/category-chooser-test.js
index 6840f93ecb1..2fc4bd40951 100644
--- a/app/assets/javascripts/discourse/tests/integration/components/select-kit/category-chooser-test.js
+++ b/app/assets/javascripts/discourse/tests/integration/components/select-kit/category-chooser-test.js
@@ -107,7 +107,7 @@ discourseModule(
 
         assert.strictEqual(
           this.subject.rows().length,
-          21,
+          22,
           "all categories are visible"
         );
 
diff --git a/app/assets/stylesheets/common/base/share_link.scss b/app/assets/stylesheets/common/base/share_link.scss
index e074d8e4171..14cc9532605 100644
--- a/app/assets/stylesheets/common/base/share_link.scss
+++ b/app/assets/stylesheets/common/base/share_link.scss
@@ -13,6 +13,11 @@
   }
 }
 
+.link-share-restricted-groups {
+  margin-top: 0.5em;
+  color: var(--danger-medium);
+}
+
 .link-share-actions {
   display: flex;
   flex-wrap: wrap;
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index a50b1a6e19e..c47acbdbc52 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -2825,6 +2825,9 @@ en:
         help: "share a link to this topic"
         instructions: "Share a link to this topic:"
         copied: "Topic link copied."
+        restricted_groups:
+          one: "Only visible to members of group:"
+          other: "Only visible to members of groups:"
         notify_users:
           title: "Notify"
           instructions: "Notify the following users about this topic:"