diff --git a/app/code/Magento/Theme/Model/PageLayout/Config/Builder.php b/app/code/Magento/Theme/Model/PageLayout/Config/Builder.php
index 13b8aa23073ce..e528f9e88d8a4 100644
--- a/app/code/Magento/Theme/Model/PageLayout/Config/Builder.php
+++ b/app/code/Magento/Theme/Model/PageLayout/Config/Builder.php
@@ -5,25 +5,38 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Theme\Model\PageLayout\Config;
 
+use Magento\Framework\App\Cache\Type\Layout;
+use Magento\Framework\App\ObjectManager;
+use Magento\Framework\View\Model\PageLayout\Config\BuilderInterface;
+use Magento\Framework\View\PageLayout\ConfigFactory;
+use Magento\Framework\View\PageLayout\File\Collector\Aggregated;
+use Magento\Theme\Model\ResourceModel\Theme\Collection;
+use Magento\Theme\Model\Theme\Data;
+use Magento\Framework\Serialize\SerializerInterface;
+
 /**
  * Page layout config builder
  */
-class Builder implements \Magento\Framework\View\Model\PageLayout\Config\BuilderInterface
+class Builder implements BuilderInterface
 {
+    const CACHE_KEY_LAYOUTS = 'THEME_LAYOUTS_FILES_MERGED';
+
     /**
-     * @var \Magento\Framework\View\PageLayout\ConfigFactory
+     * @var ConfigFactory
      */
     protected $configFactory;
 
     /**
-     * @var \Magento\Framework\View\PageLayout\File\Collector\Aggregated
+     * @var Aggregated
      */
     protected $fileCollector;
 
     /**
-     * @var \Magento\Theme\Model\ResourceModel\Theme\Collection
+     * @var Collection
      */
     protected $themeCollection;
 
@@ -33,19 +46,36 @@ class Builder implements \Magento\Framework\View\Model\PageLayout\Config\Builder
     private $configFiles = [];
 
     /**
-     * @param \Magento\Framework\View\PageLayout\ConfigFactory $configFactory
-     * @param \Magento\Framework\View\PageLayout\File\Collector\Aggregated $fileCollector
-     * @param \Magento\Theme\Model\ResourceModel\Theme\Collection $themeCollection
+     * @var Layout|null
+     */
+    private $cacheModel;
+    /**
+     * @var SerializerInterface|null
+     */
+    private $serializer;
+
+    /**
+     * @param ConfigFactory $configFactory
+     * @param Aggregated $fileCollector
+     * @param Collection $themeCollection
+     * @param Layout|null $cacheModel
+     * @param SerializerInterface|null $serializer
      */
     public function __construct(
-        \Magento\Framework\View\PageLayout\ConfigFactory $configFactory,
-        \Magento\Framework\View\PageLayout\File\Collector\Aggregated $fileCollector,
-        \Magento\Theme\Model\ResourceModel\Theme\Collection $themeCollection
+        ConfigFactory $configFactory,
+        Aggregated $fileCollector,
+        Collection $themeCollection,
+        ?Layout $cacheModel = null,
+        ?SerializerInterface $serializer = null
     ) {
         $this->configFactory = $configFactory;
         $this->fileCollector = $fileCollector;
         $this->themeCollection = $themeCollection;
-        $this->themeCollection->setItemObjectClass(\Magento\Theme\Model\Theme\Data::class);
+        $this->themeCollection->setItemObjectClass(Data::class);
+        $this->cacheModel = $cacheModel
+            ?? ObjectManager::getInstance()->get(Layout::class);
+        $this->serializer = $serializer
+            ?? ObjectManager::getInstance()->get(SerializerInterface::class);
     }
 
     /**
@@ -57,7 +87,7 @@ public function getPageLayoutsConfig()
     }
 
     /**
-     * Retrieve configuration files.
+     * Retrieve configuration files. Caches merged layouts.xml XML files.
      *
      * @return array
      */
@@ -65,10 +95,18 @@ protected function getConfigFiles()
     {
         if (!$this->configFiles) {
             $configFiles = [];
-            foreach ($this->themeCollection->loadRegisteredThemes() as $theme) {
-                $configFiles[] = $this->fileCollector->getFilesContent($theme, 'layouts.xml');
+            $this->configFiles = $this->cacheModel->load(self::CACHE_KEY_LAYOUTS);
+            if (!empty($this->configFiles)) {
+                //if value in cache is corrupted.
+                $this->configFiles = $this->serializer->unserialize($this->configFiles);
+            }
+            if (empty($this->configFiles)) {
+                foreach ($this->themeCollection->loadRegisteredThemes() as $theme) {
+                    $configFiles[] = $this->fileCollector->getFilesContent($theme, 'layouts.xml');
+                }
+                $this->configFiles = array_merge(...$configFiles);
+                $this->cacheModel->save($this->serializer->serialize($this->configFiles), self::CACHE_KEY_LAYOUTS);
             }
-            $this->configFiles = array_merge(...$configFiles);
         }
 
         return $this->configFiles;
diff --git a/app/code/Magento/Theme/Test/Unit/Model/PageLayout/Config/BuilderTest.php b/app/code/Magento/Theme/Test/Unit/Model/PageLayout/Config/BuilderTest.php
index d9eccdb871222..2e2117b79e5ab 100644
--- a/app/code/Magento/Theme/Test/Unit/Model/PageLayout/Config/BuilderTest.php
+++ b/app/code/Magento/Theme/Test/Unit/Model/PageLayout/Config/BuilderTest.php
@@ -10,8 +10,11 @@
  */
 namespace Magento\Theme\Test\Unit\Model\PageLayout\Config;
 
+use Magento\Framework\App\Cache\Type\Layout;
+use Magento\Framework\Serialize\SerializerInterface;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Framework\View\PageLayout\Config;
+use Magento\Framework\View\PageLayout\ConfigFactory;
 use Magento\Framework\View\PageLayout\File\Collector\Aggregated;
 use Magento\Theme\Model\PageLayout\Config\Builder;
 use Magento\Theme\Model\ResourceModel\Theme\Collection;
@@ -27,7 +30,7 @@ class BuilderTest extends TestCase
     protected $builder;
 
     /**
-     * @var \Magento\Framework\View\PageLayout\ConfigFactory|MockObject
+     * @var ConfigFactory|MockObject
      */
     protected $configFactory;
 
@@ -41,6 +44,15 @@ class BuilderTest extends TestCase
      */
     protected $themeCollection;
 
+    /**
+     * @var Layout|MockObject
+     */
+    protected $cacheModel;
+    /**
+     * @var SerializerInterface|MockObject
+     */
+    protected $serializer;
+
     /**
      * SetUp method
      *
@@ -48,19 +60,24 @@ class BuilderTest extends TestCase
      */
     protected function setUp(): void
     {
-        $this->configFactory = $this->getMockBuilder(\Magento\Framework\View\PageLayout\ConfigFactory::class)
+        $this->configFactory = $this->getMockBuilder(ConfigFactory::class)
             ->disableOriginalConstructor()
             ->setMethods(['create'])
             ->getMock();
 
-        $this->fileCollector = $this->getMockBuilder(
-            Aggregated::class
-        )->disableOriginalConstructor()
+        $this->fileCollector = $this->getMockBuilder(Aggregated::class)
+            ->disableOriginalConstructor()
             ->getMock();
 
         $this->themeCollection = $this->getMockBuilder(Collection::class)
             ->disableOriginalConstructor()
             ->getMock();
+        $this->cacheModel = $this->getMockBuilder(Layout::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->serializer = $this->getMockForAbstractClass(SerializerInterface::class);
+
         $this->themeCollection->expects($this->once())
             ->method('setItemObjectClass')
             ->with(Data::class)
@@ -72,7 +89,9 @@ protected function setUp(): void
             [
                 'configFactory' => $this->configFactory,
                 'fileCollector' => $this->fileCollector,
-                'themeCollection' => $this->themeCollection
+                'themeCollection' => $this->themeCollection,
+                'cacheModel' => $this->cacheModel,
+                'serializer' => $this->serializer,
             ]
         );
     }
@@ -84,8 +103,10 @@ protected function setUp(): void
      */
     public function testGetPageLayoutsConfig()
     {
+        $this->cacheModel->clean();
         $files1 = ['content layouts_1.xml', 'content layouts_2.xml'];
         $files2 = ['content layouts_3.xml', 'content layouts_4.xml'];
+        $configFiles = array_merge($files1, $files2);
 
         $theme1 = $this->getMockBuilder(Data::class)
             ->disableOriginalConstructor()
@@ -113,9 +134,17 @@ public function testGetPageLayoutsConfig()
 
         $this->configFactory->expects($this->once())
             ->method('create')
-            ->with(['configFiles' => array_merge($files1, $files2)])
+            ->with(['configFiles' => $configFiles])
             ->willReturn($config);
 
+        $this->serializer->expects($this->once())
+            ->method('serialize')
+            ->with($configFiles);
+
+        $this->cacheModel->expects($this->once())
+            ->method('save')
+            ->willReturnSelf();
+
         $this->assertSame($config, $this->builder->getPageLayoutsConfig());
     }
 }