diff --git a/core/lib/Drupal/Core/Extension/ThemeHandler.php b/core/lib/Drupal/Core/Extension/ThemeHandler.php
index a6baf9f7ba2e4e3685fadf7e086a251c76f5cf6a..3a419676d7cb5f9459a983c367570426f4f68be7 100644
--- a/core/lib/Drupal/Core/Extension/ThemeHandler.php
+++ b/core/lib/Drupal/Core/Extension/ThemeHandler.php
@@ -265,7 +265,6 @@ public function rebuildThemeData() {
         'secondary_menu' => 'Secondary menu',
         'footer' => 'Footer',
         'highlighted' => 'Highlighted',
-        'messages' => 'Messages',
         'help' => 'Help',
         'page_top' => 'Page top',
         'page_bottom' => 'Page bottom',
diff --git a/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php b/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
index bf05a3df28343504e2930ad59bee76f7609be8a1..c8012c6c8a9a23fc6d6cf93a324cb7a426d31c54 100644
--- a/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
+++ b/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
@@ -52,7 +52,7 @@ public function renderBarePage(array $content, $title, $page_theme_property, arr
     // For backwards compatibility.
     // @todo In Drupal 9, add a $show_messages function parameter.
     if (!isset($page_additions['#show_messages']) || $page_additions['#show_messages'] === TRUE) {
-      $html['page']['messages'] = ['#type' => 'status_messages'];
+      $html['page']['highlighted'] = ['#type' => 'status_messages'];
     }
 
     // We must first render the contents of the html.html.twig template, see
diff --git a/core/modules/system/templates/install-page.html.twig b/core/modules/system/templates/install-page.html.twig
index d362d22c79c7629e5fea797c7ab4237d00124c69..1d0e479b0bdfb744ebfc27e3d451f22f120024bb 100644
--- a/core/modules/system/templates/install-page.html.twig
+++ b/core/modules/system/templates/install-page.html.twig
@@ -30,7 +30,7 @@
       {% if title %}
         <h1>{{ title }}</h1>
       {% endif %}
-      {{ page.messages }}
+      {{ page.highlighted }}
       {{ page.content }}
     </main>
 
diff --git a/core/modules/system/templates/maintenance-page.html.twig b/core/modules/system/templates/maintenance-page.html.twig
index f2706210f300a3e7958cfcaec8ae286162012804..830ec21aae0b128ce91f6fb5406bc2cdcc2a4643 100644
--- a/core/modules/system/templates/maintenance-page.html.twig
+++ b/core/modules/system/templates/maintenance-page.html.twig
@@ -41,7 +41,7 @@
       <h1>{{ title }}</h1>
     {% endif %}
 
-    {{ page.messages }}
+    {{ page.highlighted }}
 
     {{ page.content }}
   </main>
diff --git a/core/modules/system/templates/page.html.twig b/core/modules/system/templates/page.html.twig
index eb5c7bf213a67ac4871e4cdd3c5c1c13f16f10e9..c5a3711ed70d57a02acd9d470fdd7ec441fc1e57 100644
--- a/core/modules/system/templates/page.html.twig
+++ b/core/modules/system/templates/page.html.twig
@@ -46,7 +46,6 @@
  * - page.primary_menu: Items for the primary menu region.
  * - page.secondary_menu: Items for the secondary menu region.
  * - page.highlighted: Items for the highlighted content region.
- * - page.messages: Status messages block can be placed in messages region.
  * - page.help: Dynamic help text, mostly for admin pages.
  * - page.content: The main content of the current page.
  * - page.sidebar_first: Items for the first sidebar.
@@ -97,7 +96,7 @@
 
   {{ page.breadcrumb }}
 
-  {{ page.messages }}
+  {{ page.highlighted }}
 
   {{ page.help }}
 
@@ -105,7 +104,6 @@
     <a id="main-content" tabindex="-1"></a>{# link is in html.html.twig #}
 
     <div class="layout-content">
-      {{ page.highlighted }}
 
       {{ title_prefix }}
       {% if title %}
diff --git a/core/profiles/minimal/config/install/block.block.stark_messages.yml b/core/profiles/minimal/config/install/block.block.stark_messages.yml
index 838d8c046981bb10eb710299896142370e0e6bac..34a5e23dc9aab6c77a7f9fc9cd7b65cb677f0789 100644
--- a/core/profiles/minimal/config/install/block.block.stark_messages.yml
+++ b/core/profiles/minimal/config/install/block.block.stark_messages.yml
@@ -3,7 +3,7 @@ theme: stark
 weight: 0
 status: true
 langcode: en
-region: messages
+region: highlighted
 plugin: system_messages_block
 settings:
   id: system_messages_block
diff --git a/core/profiles/standard/config/install/block.block.bartik_messages.yml b/core/profiles/standard/config/install/block.block.bartik_messages.yml
index 1d817dda3fa45740f61b2ab9898f204e406c44aa..0bb959079d94c953e283821ea8e3af9b3f5b695c 100644
--- a/core/profiles/standard/config/install/block.block.bartik_messages.yml
+++ b/core/profiles/standard/config/install/block.block.bartik_messages.yml
@@ -3,7 +3,7 @@ theme: bartik
 weight: 0
 status: true
 langcode: en
-region: messages
+region: highlighted
 plugin: system_messages_block
 settings:
   id: system_messages_block
diff --git a/core/profiles/standard/config/install/block.block.seven_messages.yml b/core/profiles/standard/config/install/block.block.seven_messages.yml
index 4a15ee9624c56f060a1c61245555aea870139f82..35c3531387a0c84065a39bcb14b2dfbb561bbaad 100644
--- a/core/profiles/standard/config/install/block.block.seven_messages.yml
+++ b/core/profiles/standard/config/install/block.block.seven_messages.yml
@@ -3,7 +3,7 @@ theme: seven
 weight: 0
 status: true
 langcode: en
-region: messages
+region: highlighted
 plugin: system_messages_block
 settings:
   id: system_messages_block
diff --git a/core/themes/bartik/bartik.info.yml b/core/themes/bartik/bartik.info.yml
index 3c028944cce79ed21d289d96891ee31daa9f2564..fb8f2fb05d929b206784b45e8f187c74b19bdeb4 100644
--- a/core/themes/bartik/bartik.info.yml
+++ b/core/themes/bartik/bartik.info.yml
@@ -21,7 +21,7 @@ regions:
   help: Help
   page_top: 'Page top'
   page_bottom: 'Page bottom'
-  messages: Messages
+  highlighted: Highlighted
   featured_top: 'Featured top'
   breadcrumb: Breadcrumb
   content: Content
diff --git a/core/themes/bartik/templates/maintenance-page.html.twig b/core/themes/bartik/templates/maintenance-page.html.twig
index c4eae0113a637eb98fe53097b38a830319137fbf..3cd787b33d01a738d15495d3416776ea948cc292 100644
--- a/core/themes/bartik/templates/maintenance-page.html.twig
+++ b/core/themes/bartik/templates/maintenance-page.html.twig
@@ -39,7 +39,7 @@
               <h1 class="title" id="page-title">{{ title }}</h1>
             {% endif %}
             {{ page.content }}
-            {{ page.messages }}
+            {{ page.highlighted }}
           </section>
         </main>
       </div>
diff --git a/core/themes/bartik/templates/page.html.twig b/core/themes/bartik/templates/page.html.twig
index 60b2885f82de4073bcd4f6b7964889e7318607ef..446814ee7dcb2f552f365bcd0f0a7943eb68cfd9 100644
--- a/core/themes/bartik/templates/page.html.twig
+++ b/core/themes/bartik/templates/page.html.twig
@@ -49,7 +49,7 @@
  *
  * Regions:
  * - page.header: Items for the header region.
- * - page.messages: Status and error messages. Should be displayed prominently.
+ * - page.highlighted: Items for the highlighted region.
  * - page.primary_menu: Items for the primary menu region.
  * - page.secondary_menu: Items for the secondary menu region.
  * - page.featured_top: Items for the featured top region.
@@ -109,7 +109,7 @@
         {{ page.primary_menu }}
       </div>
     </header>
-    {{ page.messages }}
+    {{ page.highlighted }}
     {% if page.featured_top %}
       <div class="featured-top">
         <aside class="featured-top__inner section layout-container clearfix" role="complementary">
diff --git a/core/themes/classy/templates/layout/maintenance-page.html.twig b/core/themes/classy/templates/layout/maintenance-page.html.twig
index a1233e22c57a5fee453f4832f5ca3d38d57eca57..7463b0238ca35b8a709b53e0148352b42486d68d 100644
--- a/core/themes/classy/templates/layout/maintenance-page.html.twig
+++ b/core/themes/classy/templates/layout/maintenance-page.html.twig
@@ -39,7 +39,7 @@
       <h1>{{ title }}</h1>
     {% endif %}
 
-    {{ page.messages }}
+    {{ page.highlighted }}
 
     {{ page.content }}
   </main>
diff --git a/core/themes/classy/templates/layout/page.html.twig b/core/themes/classy/templates/layout/page.html.twig
index dcb8f4cb52536184e58b7c187ec35445fc513ac0..57533c8521db4271d8a44d280c9017c7955e33a4 100644
--- a/core/themes/classy/templates/layout/page.html.twig
+++ b/core/themes/classy/templates/layout/page.html.twig
@@ -42,7 +42,7 @@
  *
  * Regions:
  * - page.header: Items for the header region.
- * - page.messages: Status and error messages. Should be displayed prominently.
+ * - page.highlighted: Items for the highlighted region.
  * - page.primary_menu: Items for the primary menu region.
  * - page.secondary_menu: Items for the secondary menu region.
  * - page.highlighted: Items for the highlighted content region.
@@ -94,7 +94,7 @@
 
   {{ page.breadcrumb }}
 
-  {{ page.messages }}
+  {{ page.highlighted }}
 
   {{ page.help }}
 
diff --git a/core/themes/seven/seven.info.yml b/core/themes/seven/seven.info.yml
index 8ee09146491dff0467fc3eb390fc2899cc85b9a4..99a3ec1e82b9dd01dc0661b7a3f5dd9b51c7c4c1 100644
--- a/core/themes/seven/seven.info.yml
+++ b/core/themes/seven/seven.info.yml
@@ -15,7 +15,7 @@ quickedit_stylesheets:
   - css/components/quickedit.css
 regions:
   content: Content
-  messages: Messages
+  highlighted: Highlighted
   help: Help
   page_top: 'Page top'
   page_bottom: 'Page bottom'
diff --git a/core/themes/seven/templates/install-page.html.twig b/core/themes/seven/templates/install-page.html.twig
index 0e22c947a25490e27067e0b7c63a2a6e5a882c03..b501fb83b7ecdae33e0b7c2df2cf184faedac1f5 100644
--- a/core/themes/seven/templates/install-page.html.twig
+++ b/core/themes/seven/templates/install-page.html.twig
@@ -27,7 +27,7 @@
     {% if title %}
       <h1>{{ title }}</h1>
     {% endif %}
-    {{ page.messages }}
+    {{ page.highlighted }}
     {{ page.content }}
   </main>
 
diff --git a/core/themes/seven/templates/maintenance-page.html.twig b/core/themes/seven/templates/maintenance-page.html.twig
index 1bfea5a738b47d8682c29829d7d11550997e30fb..2286e8829e065d03d1a832d190c5fe11f066a88f 100644
--- a/core/themes/seven/templates/maintenance-page.html.twig
+++ b/core/themes/seven/templates/maintenance-page.html.twig
@@ -27,7 +27,7 @@
     {% if title %}
       <h1>{{ title }}</h1>
     {% endif %}
-    {{ page.messages }}
+    {{ page.highlighted }}
     {{ page.content }}
   </main>
 
diff --git a/core/themes/seven/templates/page.html.twig b/core/themes/seven/templates/page.html.twig
index 4110987f0f6818926d90bb86bc892adb272ebc94..1c36be5d1ae699748db63edc74be61f4dbaba661 100644
--- a/core/themes/seven/templates/page.html.twig
+++ b/core/themes/seven/templates/page.html.twig
@@ -43,8 +43,7 @@
  *
  * Regions:
  * - page.page_top: Items for the header region.
- * - page.highlighted: Items for the highlighted content region.
- * - page.messages: Status and error messages. Should be displayed prominently.
+ * - page.highlighted: Items for the highlighted region.
  * - page.help: Dynamic help text, mostly for admin pages.
  * - page.content: The main content of the current page.
  * - page.sidebar_first: Items for the first sidebar.
@@ -79,7 +78,7 @@
 
     <main class="page-content clearfix" role="main">
       <div class="visually-hidden"><a id="main-content" tabindex="-1"></a></div>
-      {{ page.messages }}
+      {{ page.highlighted }}
       {% if page.help %}
         <div class="help">
           {{ page.help }}