diff --git a/core/modules/content_moderation/content_moderation.module b/core/modules/content_moderation/content_moderation.module
index 3481c243e1..347cbaf8aa 100644
--- a/core/modules/content_moderation/content_moderation.module
+++ b/core/modules/content_moderation/content_moderation.module
@@ -207,6 +207,15 @@ function content_moderation_entity_access(EntityInterface $entity, $operation, A
     }
   }
 
+  // Do not allow users to delete the state that is configured as the default
+  // state for the workflow.
+  if ($entity instanceof WorkflowInterface) {
+    $configuration = $entity->getTypePlugin()->getConfiguration();
+    if (!empty($configuration['default_moderation_state']) && $operation === sprintf('delete-state:%s', $configuration['default_moderation_state'])) {
+      return AccessResult::forbidden()->addCacheableDependency($entity);
+    }
+  }
+
   return $access_result;
 }
 
diff --git a/core/modules/content_moderation/tests/src/Functional/DefaultModerationStateTest.php b/core/modules/content_moderation/tests/src/Functional/DefaultModerationStateTest.php
new file mode 100644
index 0000000000..f5f6a5c004
--- /dev/null
+++ b/core/modules/content_moderation/tests/src/Functional/DefaultModerationStateTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Drupal\Tests\content_moderation\Functional;
+
+/**
+ * Tests setting a custom default moderation state.
+ *
+ * @group content_moderation
+ */
+class DefaultModerationStateTest extends ModerationStateTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->drupalLogin($this->adminUser);
+    $this->createContentTypeFromUi('Moderated content', 'moderated_content', TRUE);
+    $this->grantUserPermissionToCreateContentOfType($this->adminUser, 'moderated_content');
+  }
+
+  /**
+   * Test a workflow with a default moderation state set.
+   */
+  public function testPublishedDefaultState() {
+    // Set the default moderation state to be "published".
+    $this->drupalPostForm('admin/config/workflow/workflows/manage/' . $this->workflow->id(), [
+      'type_settings[workflow_settings][default_moderation_state]' => 'published',
+    ], 'Save');
+
+    $this->drupalGet('node/add/moderated_content');
+    $this->assertEquals('published', $this->assertSession()->selectExists('moderation_state[0][state]')->getValue());
+    $this->submitForm([
+      'title[0][value]' => 'moderated content',
+    ], 'Save');
+
+    $node = $this->getNodeByTitle('moderated content');
+    $this->assertEquals('published', $node->moderation_state->value);
+  }
+
+  /**
+   * Test access to deleting the default state.
+   */
+  public function testDeleteDefaultStateAccess() {
+    $this->drupalGet('admin/config/workflow/workflows/manage/editorial/state/archived/delete');
+    $this->assertSession()->statusCodeEquals(200);
+
+    $this->drupalPostForm('admin/config/workflow/workflows/manage/' . $this->workflow->id(), [
+      'type_settings[workflow_settings][default_moderation_state]' => 'archived',
+    ], 'Save');
+
+    $this->drupalGet('admin/config/workflow/workflows/manage/editorial/state/archived/delete');
+    $this->assertSession()->statusCodeEquals(403);
+  }
+
+}
diff --git a/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
index af0bb4fd7d..844e77d930 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
@@ -6,6 +6,7 @@
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
 use Drupal\Tests\content_moderation\Traits\ContentModerationTestTrait;
+use Drupal\workflows\Entity\Workflow;
 
 /**
  * @coversDefaultClass \Drupal\content_moderation\Plugin\Field\ModerationStateFieldItemList
@@ -281,4 +282,36 @@ public function moderatedEntityWithExistingIdTestCases() {
     ];
   }
 
+  /**
+   * Test customising the default moderation state.
+   */
+  public function testWorkflowCustomisedInitialState() {
+    $workflow = Workflow::load('editorial');
+    $configuration = $workflow->getTypePlugin()->getConfiguration();
+
+    // Test a node for a workflow that hasn't been updated to include the
+    // 'default_moderation_state' setting. We must be backwards compatible with
+    // configuration that was exported before this change was introduced.
+    $this->assertFalse(isset($configuration['default_moderation_state']));
+    $legacy_configuration_node = Node::create([
+      'title' => 'Test title',
+      'type' => 'example',
+    ]);
+    $this->assertEquals('draft', $legacy_configuration_node->moderation_state->value);
+    $legacy_configuration_node->save();
+    $this->assertEquals('draft', $legacy_configuration_node->moderation_state->value);
+
+    $configuration['default_moderation_state'] = 'published';
+    $workflow->getTypePlugin()->setConfiguration($configuration);
+    $workflow->save();
+
+    $updated_default_node = Node::create([
+      'title' => 'Test title',
+      'type' => 'example',
+    ]);
+    $this->assertEquals('published', $updated_default_node->moderation_state->value);
+    $legacy_configuration_node->save();
+    $this->assertEquals('published', $updated_default_node->moderation_state->value);
+  }
+
 }