diff --git a/app/assets/javascripts/discourse/app/components/sidebar.js b/app/assets/javascripts/discourse/app/components/sidebar.js
new file mode 100644
index 00000000000..ea096319112
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/components/sidebar.js
@@ -0,0 +1,3 @@
+import GlimmerComponent from "discourse/components/glimmer";
+
+export default class Sidebar extends GlimmerComponent {}
diff --git a/app/assets/javascripts/discourse/app/controllers/application.js b/app/assets/javascripts/discourse/app/controllers/application.js
index b494f56e54d..c07ca32adc9 100644
--- a/app/assets/javascripts/discourse/app/controllers/application.js
+++ b/app/assets/javascripts/discourse/app/controllers/application.js
@@ -6,6 +6,12 @@ export default Controller.extend({
   showTop: true,
   showFooter: false,
   router: service(),
+  showSidebar: true,
+
+  @discourseComputed("showSidebar", "currentUser.experimental_sidebar_enabled")
+  mainOutletWrapperClasses(showSidebar, experimentalSidebarEnabled) {
+    return showSidebar && experimentalSidebarEnabled ? "has-sidebar" : "";
+  },
 
   @discourseComputed
   canSignUp() {
diff --git a/app/assets/javascripts/discourse/app/routes/application.js b/app/assets/javascripts/discourse/app/routes/application.js
index dbffdf2de99..ea6da0a5c76 100644
--- a/app/assets/javascripts/discourse/app/routes/application.js
+++ b/app/assets/javascripts/discourse/app/routes/application.js
@@ -37,6 +37,10 @@ const ApplicationRoute = DiscourseRoute.extend(OpenComposer, {
       });
     },
 
+    toggleSidebar() {
+      this.controllerFor("application").toggleProperty("showSidebar");
+    },
+
     toggleMobileView() {
       mobile.toggleMobileView();
     },
diff --git a/app/assets/javascripts/discourse/app/templates/application.hbs b/app/assets/javascripts/discourse/app/templates/application.hbs
index 6c0944f9059..7e16b0f9106 100644
--- a/app/assets/javascripts/discourse/app/templates/application.hbs
+++ b/app/assets/javascripts/discourse/app/templates/application.hbs
@@ -8,26 +8,34 @@
                 showKeyboard=(route-action "showKeyboardShortcutsHelp")
                 toggleMobileView=(route-action "toggleMobileView")
                 toggleAnonymous=(route-action "toggleAnonymous")
-                logout=(route-action "logout")}}
+                logout=(route-action "logout")
+                toggleSidebar=(route-action "toggleSidebar")
+                }}
   {{software-update-prompt}}
 
   {{plugin-outlet name="below-site-header" connectorTagName="div" args=(hash currentPath=router._router.currentPath)}}
 
-  <div id="main-outlet" class="wrap" role="main">
-    {{plugin-outlet name="above-main-container" connectorTagName="div"}}
-    <div class="container" id="main-container">
-      {{#if showTop}}
-        {{custom-html name="top"}}
-      {{/if}}
-      {{notification-consent-banner}}
-      {{pwa-install-banner}}
-      {{global-notice}}
-      {{create-topics-notice}}
-      {{plugin-outlet name="top-notices" connectorTagName="div" args=(hash currentPath=router._router.currentPath)}}
-    </div>
+  <div id="main-outlet-wrapper" class="wrap {{mainOutletWrapperClasses}}" role="main">
+    {{#if currentUser.experimental_sidebar_enabled}}
+      <Sidebar @shouldDisplay={{showSidebar}} />
+    {{/if}}
 
-    {{outlet}}
-    {{outlet "user-card"}}
+    <div id="main-outlet">
+      {{plugin-outlet name="above-main-container" connectorTagName="div"}}
+      <div class="container" id="main-container">
+        {{#if showTop}}
+          {{custom-html name="top"}}
+        {{/if}}
+        {{notification-consent-banner}}
+        {{pwa-install-banner}}
+        {{global-notice}}
+        {{create-topics-notice}}
+        {{plugin-outlet name="top-notices" connectorTagName="div" args=(hash currentPath=router._router.currentPath)}}
+      </div>
+
+      {{outlet}}
+      {{outlet "user-card"}}
+    </div>
   </div>
 
   {{plugin-outlet name="above-footer" connectorTagName="div" args=(hash showFooter=showFooter)}}
diff --git a/app/assets/javascripts/discourse/app/templates/components/sidebar.hbs b/app/assets/javascripts/discourse/app/templates/components/sidebar.hbs
new file mode 100644
index 00000000000..91657f9f4c6
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/templates/components/sidebar.hbs
@@ -0,0 +1,6 @@
+{{#if @shouldDisplay}}
+  <div class="sidebar-wrapper">
+    <div class="sidebar-container">
+    </div>
+  </div>
+{{/if}}
diff --git a/app/assets/javascripts/discourse/app/widgets/header-contents.js b/app/assets/javascripts/discourse/app/widgets/header-contents.js
index 5ce69e3b2d5..7f13995929f 100644
--- a/app/assets/javascripts/discourse/app/widgets/header-contents.js
+++ b/app/assets/javascripts/discourse/app/widgets/header-contents.js
@@ -4,6 +4,9 @@ import hbs from "discourse/widgets/hbs-compiler";
 createWidget("header-contents", {
   tagName: "div.contents.clearfix",
   template: hbs`
+    {{#if attrs.sidebarEnabled}}
+      {{sidebar-toggle attrs=attrs}}
+    {{/if}}
     {{home-logo attrs=attrs}}
     {{#if attrs.topic}}
       {{header-topic-info attrs=attrs}}
diff --git a/app/assets/javascripts/discourse/app/widgets/header.js b/app/assets/javascripts/discourse/app/widgets/header.js
index 4885bbf1981..9d289ae005d 100644
--- a/app/assets/javascripts/discourse/app/widgets/header.js
+++ b/app/assets/javascripts/discourse/app/widgets/header.js
@@ -400,7 +400,12 @@ export default createWidget("header", {
       return panels;
     };
 
-    let contentsAttrs = { contents, minimized: !!attrs.topic };
+    let contentsAttrs = {
+      contents,
+      minimized: !!attrs.topic,
+      sidebarEnabled: this.currentUser?.experimental_sidebar_enabled,
+    };
+
     return h(
       "div.wrap",
       this.attach("header-contents", Object.assign({}, attrs, contentsAttrs))
diff --git a/app/assets/javascripts/discourse/app/widgets/sidebar-toggle.js b/app/assets/javascripts/discourse/app/widgets/sidebar-toggle.js
new file mode 100644
index 00000000000..b39163c0f32
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/widgets/sidebar-toggle.js
@@ -0,0 +1,16 @@
+import { createWidget } from "discourse/widgets/widget";
+
+export default createWidget("sidebar-toggle", {
+  tagName: "span.header-sidebar-toggle",
+
+  html() {
+    return [
+      this.attach("button", {
+        title: "",
+        icon: "bars",
+        action: "toggleSidebar",
+        className: "btn btn-flat",
+      }),
+    ];
+  },
+});
diff --git a/app/assets/javascripts/discourse/tests/acceptance/sidebar-test.js b/app/assets/javascripts/discourse/tests/acceptance/sidebar-test.js
new file mode 100644
index 00000000000..c173b7e4d17
--- /dev/null
+++ b/app/assets/javascripts/discourse/tests/acceptance/sidebar-test.js
@@ -0,0 +1,65 @@
+import { click, visit } from "@ember/test-helpers";
+import {
+  acceptance,
+  conditionalTest,
+  exists,
+} from "discourse/tests/helpers/qunit-helpers";
+import { test } from "qunit";
+import { isLegacyEmber } from "discourse-common/config/environment";
+
+acceptance("Sidebar - Anon User", function () {
+  // Don't show sidebar for anon user until we know what we want to display
+  test("sidebar is not displayed", async function (assert) {
+    await visit("/");
+
+    assert.ok(!exists("#main-outlet-wrapper.has-sidebar"));
+    assert.ok(!exists(".sidebar-wrapper"));
+  });
+});
+
+acceptance("Sidebar - User with sidebar disabled", function (needs) {
+  needs.user({ experimental_sidebar_enabled: false });
+
+  conditionalTest(
+    "sidebar is not displayed",
+    !isLegacyEmber(),
+    async function (assert) {
+      await visit("/");
+
+      assert.ok(!exists("#main-outlet-wrapper.has-sidebar"));
+      assert.ok(!exists(".sidebar-wrapper"));
+    }
+  );
+});
+
+acceptance("Sidebar - User with sidebar enabled", function (needs) {
+  needs.user({ experimental_sidebar_enabled: true });
+
+  conditionalTest(
+    "hiding and displaying sidebar",
+    !isLegacyEmber(),
+    async function (assert) {
+      await visit("/");
+
+      assert.ok(
+        exists("#main-outlet-wrapper.has-sidebar"),
+        "adds sidebar utility class on main outlet wrapper"
+      );
+
+      assert.ok(exists(".sidebar-wrapper"), "displays the sidebar by default");
+
+      await click(".header-sidebar-toggle .btn");
+
+      assert.ok(
+        !exists("#main-outlet-wrapper.has-sidebar"),
+        "removes sidebar utility class from main outlet wrapper"
+      );
+
+      assert.ok(!exists(".sidebar-wrapper"), "hides the sidebar");
+
+      await click(".header-sidebar-toggle .btn");
+
+      assert.ok(exists(".sidebar-wrapper"), "displays the sidebar");
+    }
+  );
+});
diff --git a/app/assets/stylesheets/common/base/_index.scss b/app/assets/stylesheets/common/base/_index.scss
index f6b8e49d0a0..6741fdc6bbe 100644
--- a/app/assets/stylesheets/common/base/_index.scss
+++ b/app/assets/stylesheets/common/base/_index.scss
@@ -44,6 +44,7 @@
 @import "search";
 @import "share_link";
 @import "shared-drafts";
+@import "sidebar";
 @import "tagging";
 @import "tooltip";
 @import "topic-admin-menu";
diff --git a/app/assets/stylesheets/common/base/discourse.scss b/app/assets/stylesheets/common/base/discourse.scss
index 0126ae6cc55..b9cdd3cfb34 100644
--- a/app/assets/stylesheets/common/base/discourse.scss
+++ b/app/assets/stylesheets/common/base/discourse.scss
@@ -651,6 +651,7 @@ table {
 
 #main-outlet {
   padding-top: 2.5em;
+  grid-area: content;
 }
 
 #main {
diff --git a/app/assets/stylesheets/common/base/header.scss b/app/assets/stylesheets/common/base/header.scss
index 07cffbaf119..0cc0a38922e 100644
--- a/app/assets/stylesheets/common/base/header.scss
+++ b/app/assets/stylesheets/common/base/header.scss
@@ -14,7 +14,6 @@
   backface-visibility: hidden; /** do magic for scrolling performance **/
 
   > .wrap {
-    box-sizing: border-box;
     width: 100%;
     height: 100%;
 
diff --git a/app/assets/stylesheets/common/base/sidebar.scss b/app/assets/stylesheets/common/base/sidebar.scss
new file mode 100644
index 00000000000..d1c87b6a639
--- /dev/null
+++ b/app/assets/stylesheets/common/base/sidebar.scss
@@ -0,0 +1,40 @@
+.header-sidebar-toggle {
+  margin-right: 1em;
+  margin-left: -10px;
+
+  button {
+    position: relative;
+    font-size: var(--font-up-2);
+
+    .discourse-no-touch & {
+      &:hover {
+        background: var(--primary-low);
+        .d-icon {
+          color: var(--primary-medium);
+        }
+      }
+    }
+  }
+}
+
+.sidebar-wrapper {
+  grid-area: sidebar;
+  position: sticky;
+  top: var(--header-offset);
+  height: calc(100vh - var(--header-offset));
+  align-self: start;
+  overflow-y: auto;
+  background-color: var(--primary-very-low);
+}
+
+.sidebar-container {
+  box-sizing: border-box;
+  height: 100%;
+  width: 240px;
+  padding: 1em;
+}
+
+.sidebar-toggle {
+  display: flex;
+  justify-content: flex-end;
+}
diff --git a/app/assets/stylesheets/desktop/discourse.scss b/app/assets/stylesheets/desktop/discourse.scss
index 8fb5a9dd553..18893c7aae1 100644
--- a/app/assets/stylesheets/desktop/discourse.scss
+++ b/app/assets/stylesheets/desktop/discourse.scss
@@ -182,3 +182,16 @@ input {
     min-width: 0;
   }
 }
+
+#main-outlet-wrapper {
+  display: grid;
+  grid-template-areas: "content";
+  grid-template-columns: 1fr;
+  gap: 0;
+
+  &.has-sidebar {
+    grid-template-areas: "sidebar content";
+    grid-template-columns: 240px 1fr;
+    gap: 0 2em;
+  }
+}