diff --git a/django/contrib/admin/static/admin/css/nav_sidebar.css b/django/contrib/admin/static/admin/css/nav_sidebar.css
index 5fd2ff0bde..f76e6ce485 100644
--- a/django/contrib/admin/static/admin/css/nav_sidebar.css
+++ b/django/contrib/admin/static/admin/css/nav_sidebar.css
@@ -59,8 +59,13 @@
     content: '\00AB';
 }
 
+.main > #nav-sidebar {
+    visibility: hidden;
+}
+
 .main.shifted > #nav-sidebar {
     margin-left: 0;
+    visibility: visible;
 }
 
 [dir="rtl"] .main.shifted > #nav-sidebar {
diff --git a/django/contrib/admin/static/admin/js/nav_sidebar.js b/django/contrib/admin/static/admin/js/nav_sidebar.js
index 261a9d4992..7e735db15c 100644
--- a/django/contrib/admin/static/admin/js/nav_sidebar.js
+++ b/django/contrib/admin/static/admin/js/nav_sidebar.js
@@ -2,47 +2,24 @@
 {
     const toggleNavSidebar = document.getElementById('toggle-nav-sidebar');
     if (toggleNavSidebar !== null) {
-        const navLinks = document.querySelectorAll('#nav-sidebar a');
-        function disableNavLinkTabbing() {
-            for (const navLink of navLinks) {
-                navLink.tabIndex = -1;
-            }
-        }
-        function enableNavLinkTabbing() {
-            for (const navLink of navLinks) {
-                navLink.tabIndex = 0;
-            }
-        }
-        function disableNavFilterTabbing() {
-            document.getElementById('nav-filter').tabIndex = -1;
-        }
-        function enableNavFilterTabbing() {
-            document.getElementById('nav-filter').tabIndex = 0;
-        }
-
+        const navSidebar = document.getElementById('nav-sidebar');
         const main = document.getElementById('main');
         let navSidebarIsOpen = localStorage.getItem('django.admin.navSidebarIsOpen');
         if (navSidebarIsOpen === null) {
             navSidebarIsOpen = 'true';
         }
-        if (navSidebarIsOpen === 'false') {
-            disableNavLinkTabbing();
-            disableNavFilterTabbing();
-        }
         main.classList.toggle('shifted', navSidebarIsOpen === 'true');
+        navSidebar.setAttribute('aria-expanded', navSidebarIsOpen);
 
         toggleNavSidebar.addEventListener('click', function() {
             if (navSidebarIsOpen === 'true') {
                 navSidebarIsOpen = 'false';
-                disableNavLinkTabbing();
-                disableNavFilterTabbing();
             } else {
                 navSidebarIsOpen = 'true';
-                enableNavLinkTabbing();
-                enableNavFilterTabbing();
             }
             localStorage.setItem('django.admin.navSidebarIsOpen', navSidebarIsOpen);
             main.classList.toggle('shifted');
+            navSidebar.setAttribute('aria-expanded', navSidebarIsOpen);
         });
     }
 
diff --git a/django/contrib/admin/templates/admin/nav_sidebar.html b/django/contrib/admin/templates/admin/nav_sidebar.html
index 6ddff01d63..a413e23754 100644
--- a/django/contrib/admin/templates/admin/nav_sidebar.html
+++ b/django/contrib/admin/templates/admin/nav_sidebar.html
@@ -1,6 +1,6 @@
 {% load i18n %}
 <button class="sticky toggle-nav-sidebar" id="toggle-nav-sidebar" aria-label="{% translate 'Toggle navigation' %}"></button>
-<nav class="sticky" id="nav-sidebar">
+<nav class="sticky" id="nav-sidebar" aria-label="{% translate 'Sidebar' %}">
   <input type="search" id="nav-filter"
          placeholder="{% translate 'Start typing to filter…' %}"
          aria-label="{% translate 'Filter navigation items' %}">
diff --git a/tests/admin_views/test_nav_sidebar.py b/tests/admin_views/test_nav_sidebar.py
index 3cb20e4068..e9b367b63b 100644
--- a/tests/admin_views/test_nav_sidebar.py
+++ b/tests/admin_views/test_nav_sidebar.py
@@ -43,21 +43,29 @@ class AdminSidebarTests(TestCase):
     def test_sidebar_not_on_index(self):
         response = self.client.get(reverse("test_with_sidebar:index"))
         self.assertContains(response, '<div class="main" id="main">')
-        self.assertNotContains(response, '<nav class="sticky" id="nav-sidebar">')
+        self.assertNotContains(
+            response, '<nav class="sticky" id="nav-sidebar" aria-label="Sidebar">'
+        )
 
     def test_sidebar_disabled(self):
         response = self.client.get(reverse("test_without_sidebar:index"))
-        self.assertNotContains(response, '<nav class="sticky" id="nav-sidebar">')
+        self.assertNotContains(
+            response, '<nav class="sticky" id="nav-sidebar" aria-label="Sidebar">'
+        )
 
     def test_sidebar_unauthenticated(self):
         self.client.logout()
         response = self.client.get(reverse("test_with_sidebar:login"))
-        self.assertNotContains(response, '<nav class="sticky" id="nav-sidebar">')
+        self.assertNotContains(
+            response, '<nav class="sticky" id="nav-sidebar" aria-label="Sidebar">'
+        )
 
     def test_sidebar_aria_current_page(self):
         url = reverse("test_with_sidebar:auth_user_changelist")
         response = self.client.get(url)
-        self.assertContains(response, '<nav class="sticky" id="nav-sidebar">')
+        self.assertContains(
+            response, '<nav class="sticky" id="nav-sidebar" aria-label="Sidebar">'
+        )
         self.assertContains(
             response, '<a href="%s" aria-current="page">Users</a>' % url
         )
@@ -80,7 +88,9 @@ class AdminSidebarTests(TestCase):
     def test_sidebar_aria_current_page_missing_without_request_context_processor(self):
         url = reverse("test_with_sidebar:auth_user_changelist")
         response = self.client.get(url)
-        self.assertContains(response, '<nav class="sticky" id="nav-sidebar">')
+        self.assertContains(
+            response, '<nav class="sticky" id="nav-sidebar" aria-label="Sidebar">'
+        )
         # Does not include aria-current attribute.
         self.assertContains(response, '<a href="%s">Users</a>' % url)
         self.assertNotContains(response, "aria-current")
@@ -146,16 +156,15 @@ class SeleniumTests(AdminSeleniumTestCase):
         )
         self.assertEqual(toggle_button.tag_name, "button")
         self.assertEqual(toggle_button.get_attribute("aria-label"), "Toggle navigation")
-        for link in self.selenium.find_elements(By.CSS_SELECTOR, "#nav-sidebar a"):
-            self.assertEqual(link.get_attribute("tabIndex"), "0")
-        filter_input = self.selenium.find_element(By.CSS_SELECTOR, "#nav-filter")
-        self.assertEqual(filter_input.get_attribute("tabIndex"), "0")
+        nav_sidebar = self.selenium.find_element(By.ID, "nav-sidebar")
+        self.assertEqual(nav_sidebar.get_attribute("aria-expanded"), "true")
+        self.assertTrue(nav_sidebar.is_displayed())
         toggle_button.click()
-        # Hidden sidebar is not reachable via keyboard navigation.
-        for link in self.selenium.find_elements(By.CSS_SELECTOR, "#nav-sidebar a"):
-            self.assertEqual(link.get_attribute("tabIndex"), "-1")
-        filter_input = self.selenium.find_element(By.CSS_SELECTOR, "#nav-filter")
-        self.assertEqual(filter_input.get_attribute("tabIndex"), "-1")
+
+        # Hidden sidebar is not visible.
+        nav_sidebar = self.selenium.find_element(By.ID, "nav-sidebar")
+        self.assertEqual(nav_sidebar.get_attribute("aria-expanded"), "false")
+        self.assertFalse(nav_sidebar.is_displayed())
         main_element = self.selenium.find_element(By.CSS_SELECTOR, "#main")
         self.assertNotIn("shifted", main_element.get_attribute("class").split())
 
@@ -189,16 +198,14 @@ class SeleniumTests(AdminSeleniumTestCase):
         toggle_button = self.selenium.find_element(
             By.CSS_SELECTOR, "#toggle-nav-sidebar"
         )
-        # Hidden sidebar is not reachable via keyboard navigation.
-        for link in self.selenium.find_elements(By.CSS_SELECTOR, "#nav-sidebar a"):
-            self.assertEqual(link.get_attribute("tabIndex"), "-1")
-        filter_input = self.selenium.find_element(By.CSS_SELECTOR, "#nav-filter")
-        self.assertEqual(filter_input.get_attribute("tabIndex"), "-1")
+        # Hidden sidebar is not visible.
+        nav_sidebar = self.selenium.find_element(By.ID, "nav-sidebar")
+        self.assertEqual(nav_sidebar.get_attribute("aria-expanded"), "false")
+        self.assertFalse(nav_sidebar.is_displayed())
         toggle_button.click()
-        for link in self.selenium.find_elements(By.CSS_SELECTOR, "#nav-sidebar a"):
-            self.assertEqual(link.get_attribute("tabIndex"), "0")
-        filter_input = self.selenium.find_element(By.CSS_SELECTOR, "#nav-filter")
-        self.assertEqual(filter_input.get_attribute("tabIndex"), "0")
+        nav_sidebar = self.selenium.find_element(By.ID, "nav-sidebar")
+        self.assertEqual(nav_sidebar.get_attribute("aria-expanded"), "true")
+        self.assertTrue(nav_sidebar.is_displayed())
         self.assertEqual(
             self.selenium.execute_script(
                 "return localStorage.getItem('django.admin.navSidebarIsOpen')"