diff --git a/core/modules/layout_builder/config/schema/layout_builder.schema.yml b/core/modules/layout_builder/config/schema/layout_builder.schema.yml
index f9f2ee8e9e..2f99a4a191 100644
--- a/core/modules/layout_builder/config/schema/layout_builder.schema.yml
+++ b/core/modules/layout_builder/config/schema/layout_builder.schema.yml
@@ -52,6 +52,11 @@ layout_builder.component:
     additional:
       type: ignore
       label: 'Additional data'
+    third_party_settings:
+      type: sequence
+      label: 'Third party settings'
+      sequence:
+        type: ignore
 
 inline_block:
   type: block_settings
diff --git a/core/modules/layout_builder/src/SectionComponent.php b/core/modules/layout_builder/src/SectionComponent.php
index 4937f7fbcd..3507da19c7 100644
--- a/core/modules/layout_builder/src/SectionComponent.php
+++ b/core/modules/layout_builder/src/SectionComponent.php
@@ -3,6 +3,7 @@
 namespace Drupal\layout_builder;
 
 use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Core\Config\Entity\ThirdPartySettingsInterface;
 use Drupal\Core\Plugin\ContextAwarePluginInterface;
 use Drupal\layout_builder\Event\SectionComponentBuildRenderArrayEvent;
 
@@ -28,7 +29,7 @@
  * @todo Determine whether an interface will be provided for this in
  *   https://www.drupal.org/project/drupal/issues/2930334.
  */
-class SectionComponent {
+class SectionComponent implements ThirdPartySettingsInterface {
 
   /**
    * The UUID of the component.
@@ -65,6 +66,22 @@ class SectionComponent {
    */
   protected $additional = [];
 
+  /**
+   * Third party settings.
+   *
+   * An array of key/value pairs keyed by provider.
+   *
+   * @var array[]
+   */
+  protected $thirdPartySettings = [];
+
+  /**
+   * The third party settings module key for the legacy 'additional' property.
+   *
+   * @var string
+   */
+  private $legacyAdditionalModuleKey = '_layout_builder';
+
   /**
    * Constructs a new SectionComponent.
    *
@@ -76,12 +93,17 @@ class SectionComponent {
    *   The plugin configuration.
    * @param mixed[] $additional
    *   An additional values.
+   * @param array[] $third_party_settings
+   *   (optional) Any third party settings.
    */
-  public function __construct($uuid, $region, array $configuration = [], array $additional = []) {
+  public function __construct($uuid, $region, array $configuration = [], array $additional = [], array $third_party_settings = []) {
     $this->uuid = $uuid;
     $this->region = $region;
     $this->configuration = $configuration;
-    $this->additional = $additional;
+    if ($additional) {
+      $third_party_settings[$this->legacyAdditionalModuleKey] = $additional;
+    }
+    $this->thirdPartySettings = $third_party_settings;
   }
 
   /**
@@ -117,7 +139,7 @@ public function get($property) {
       $value = isset($this->{$property}) ? $this->{$property} : NULL;
     }
     else {
-      $value = isset($this->additional[$property]) ? $this->additional[$property] : NULL;
+      $value = $this->getThirdPartySetting($this->legacyAdditionalModuleKey, $property);
     }
     return $value;
   }
@@ -137,7 +159,8 @@ public function set($property, $value) {
       $this->{$property} = $value;
     }
     else {
-      $this->additional[$property] = $value;
+      @trigger_error('Additional component properties should set via ::setThirdPartySetting().', E_USER_DEPRECATED);
+      $this->setThirdPartySetting($this->legacyAdditionalModuleKey, $property, $value);
     }
     return $this;
   }
@@ -302,8 +325,9 @@ public function toArray() {
       'uuid' => $this->getUuid(),
       'region' => $this->getRegion(),
       'configuration' => $this->getConfiguration(),
-      'additional' => $this->additional,
+      'additional' => $this->getThirdPartysettings($this->legacyAdditionalModuleKey),
       'weight' => $this->getWeight(),
+      'third_party_settings' => $this->thirdPartySettings,
     ];
   }
 
@@ -319,12 +343,66 @@ public function toArray() {
    *   The section component object.
    */
   public static function fromArray(array $component) {
+    // Ensure expected array keys are present.
+    $component += [
+      'uuid' => '',
+      'region' => [],
+      'configuration' => [],
+      'additional' => [],
+      'third_party_settings' => [],
+    ];
     return (new static(
       $component['uuid'],
       $component['region'],
       $component['configuration'],
-      $component['additional']
+      $component['additional'],
+      $component['third_party_settings']
     ))->setWeight($component['weight']);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getThirdPartySetting($provider, $key, $default = NULL) {
+    return isset($this->thirdPartySettings[$provider][$key]) ? $this->thirdPartySettings[$provider][$key] : $default;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getThirdPartySettings($provider) {
+    return isset($this->thirdPartySettings[$provider]) ? $this->thirdPartySettings[$provider] : [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setThirdPartySetting($provider, $key, $value) {
+    $this->thirdPartySettings[$provider][$key] = $value;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function unsetThirdPartySetting($provider, $key) {
+    unset($this->thirdPartySettings[$provider][$key]);
+    // If the third party is no longer storing any information, completely
+    // remove the array holding the settings for this provider.
+    if (empty($this->thirdPartySettings[$provider])) {
+      unset($this->thirdPartySettings[$provider]);
+    }
+    return $this;
+  }
+
+  /**
+   * Gets the list of third parties that store information.
+   *
+   * @return array
+   *   The list of third parties.
+   */
+  public function getThirdPartyProviders() {
+    return array_diff(array_keys($this->thirdPartySettings), [$this->legacyAdditionalModuleKey]);
+  }
+
 }
diff --git a/core/modules/layout_builder/tests/fixtures/update/layout-builder-enable.php b/core/modules/layout_builder/tests/fixtures/update/layout-builder-enable.php
index 980a87064e..d770c6fd65 100644
--- a/core/modules/layout_builder/tests/fixtures/update/layout-builder-enable.php
+++ b/core/modules/layout_builder/tests/fixtures/update/layout-builder-enable.php
@@ -30,6 +30,7 @@
       ],
       'additional' => [],
       'weight' => 0,
+      'third_party_settings' => [],
     ],
   ],
   'third_party_settings' => [],
diff --git a/core/modules/layout_builder/tests/src/Functional/Update/LayoutBuilderEnableUpdatePathTest.php b/core/modules/layout_builder/tests/src/Functional/Update/LayoutBuilderEnableUpdatePathTest.php
index 413d0eae0a..5cc1d38d2a 100644
--- a/core/modules/layout_builder/tests/src/Functional/Update/LayoutBuilderEnableUpdatePathTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/Update/LayoutBuilderEnableUpdatePathTest.php
@@ -45,6 +45,7 @@ public function testRunUpdates() {
               ],
               'additional' => [],
               'weight' => 0,
+              'third_party_settings' => [],
             ],
           ],
           'third_party_settings' => [],
diff --git a/core/modules/layout_builder/tests/src/Kernel/DefaultsSectionStorageTest.php b/core/modules/layout_builder/tests/src/Kernel/DefaultsSectionStorageTest.php
index 637da29947..150da5d682 100644
--- a/core/modules/layout_builder/tests/src/Kernel/DefaultsSectionStorageTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/DefaultsSectionStorageTest.php
@@ -107,7 +107,7 @@ public function providerTestAccess() {
         'layout_onecol',
         [],
         [
-          'first-uuid' => new SectionComponent('first-uuid', 'content', ['id' => 'foo'], ['harold' => 'maude']),
+          'first-uuid' => new SectionComponent('first-uuid', 'content', ['id' => 'foo'], ['harold' => 'maude'], ['layout_builder_defaults_test' => ['harold' => 'kumar']]),
         ],
         ['layout_builder_defaults_test' => ['which_party' => 'third']]
       ),