diff --git a/tests/phpunit/tests/blocks/wpBlockPatternsRegistry.php b/tests/phpunit/tests/blocks/wpBlockPatternsRegistry.php
new file mode 100644
index 0000000000..8eb4fce78b
--- /dev/null
+++ b/tests/phpunit/tests/blocks/wpBlockPatternsRegistry.php
@@ -0,0 +1,439 @@
+<?php
+/**
+ * Tests for WP_Block_Patterns_Registry.
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ * @since 6.4.0
+ *
+ * @group blocks
+ *
+ * @coversDefaultClass WP_Block_Patterns_Registry
+ */
+class Tests_Blocks_wpBlockPattersRegistry extends WP_UnitTestCase {
+
+	/**
+	 * Fake block patterns registry.
+	 *
+	 * @since 6.4.0
+	 * @var WP_Block_Patterns_Registry
+	 */
+	private $registry = null;
+
+	/**
+	 * Set up each test method.
+	 *
+	 * @since 6.4.0
+	 */
+	public function set_up() {
+		parent::set_up();
+
+		$this->registry = new WP_Block_Patterns_Registry();
+	}
+
+	/**
+	 * Tear down each test method.
+	 *
+	 * @since 6.4.0
+	 */
+	public function tear_down() {
+		$this->registry = null;
+
+		$registry = WP_Block_Type_Registry::get_instance();
+
+		if ( $registry->is_registered( 'tests/my-block' ) ) {
+			$registry->unregister( 'tests/my-block' );
+		}
+
+		parent::tear_down();
+	}
+
+	/**
+	 * Should reject missing pattern name.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_missing_name() {
+		$name     = null;
+		$settings = array(
+			'title'   => 'Test Pattern',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should reject non-string name.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_invalid_non_string_name() {
+		$name     = 123;
+		$settings = array(
+			'title'   => 'Test Pattern',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should missing title.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_missing_title() {
+		$name     = 'test/pattern';
+		$settings = array(
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should reject non-string title.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_invalid_non_string_title() {
+		$name     = 'test/pattern';
+		$settings = array(
+			'title'   => 456,
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should reject missing content.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_missing_content() {
+		$name     = 'Test Pattern';
+		$settings = array(
+			'title' => 'Test Pattern',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should reject non-string content.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::register
+	 */
+	public function test_invalid_non_string_content() {
+		$name     = 'Test Pattern';
+		$settings = array(
+			'title'   => 'Test Pattern',
+			'content' => 789,
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should accept valid pattern.
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 *
+	 * @ticket 59476
+	 */
+	public function test_register_block_pattern() {
+		$name     = 'test/pattern';
+		$settings = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$success = $this->registry->register( $name, $settings );
+		$this->assertTrue( $success );
+	}
+
+	/**
+	 * Unregistering should fail if a pattern is not registered.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::unregister
+	 *
+	 * @expectedIncorrectUsage WP_Block_Patterns_Registry::unregister
+	 */
+	public function test_unregister_not_registered_block() {
+		$success = $this->registry->unregister( 'test/unregistered' );
+		$this->assertFalse( $success );
+	}
+
+	/**
+	 * Should unregister existing patterns.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::unregister
+	 */
+	public function test_unregister_block_pattern() {
+		$name     = 'test/pattern';
+		$settings = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+
+		$this->registry->register( $name, $settings );
+		$success = $this->registry->unregister( $name );
+		$this->assertTrue( $success );
+	}
+
+	/**
+	 * Should find all registered patterns.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::get_all_registered
+	 */
+	public function test_get_all_registered() {
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$pattern_two = array(
+			'title'   => 'Pattern Two',
+			'content' => '<!-- wp:paragraph --><p>Two</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/two', $pattern_two );
+
+		$pattern_three = array(
+			'title'   => 'Pattern Three',
+			'content' => '<!-- wp:paragraph --><p>Three</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/three', $pattern_three );
+
+		$pattern_one['name']   = 'test/one';
+		$pattern_two['name']   = 'test/two';
+		$pattern_three['name'] = 'test/three';
+
+		$expected = array(
+			$pattern_one,
+			$pattern_two,
+			$pattern_three,
+		);
+
+		$registered = $this->registry->get_all_registered();
+		$this->assertSame( $expected, $registered );
+	}
+
+	/**
+	 * Should not find pattern that's not registered.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::get_registered
+	 */
+	public function test_get_registered_rejects_unknown_pattern_name() {
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$pattern_two = array(
+			'title'   => 'Pattern Two',
+			'content' => '<!-- wp:paragraph --><p>Two</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/two', $pattern_two );
+
+		$pattern = $this->registry->get_registered( 'test/three' );
+		$this->assertNull( $pattern );
+	}
+
+	/**
+	 * Should find registered pattern by name.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::get_registered
+	 */
+	public function test_get_registered() {
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$pattern_two = array(
+			'title'   => 'Pattern Two',
+			'content' => '<!-- wp:paragraph --><p>Two</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/two', $pattern_two );
+
+		$pattern_three = array(
+			'title'   => 'Pattern Three',
+			'content' => '<!-- wp:paragraph --><p>Three</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/three', $pattern_three );
+
+		$pattern_two['name'] = 'test/two';
+
+		$pattern = $this->registry->get_registered( 'test/two' );
+		$this->assertSame( $pattern_two, $pattern );
+	}
+
+	/**
+	 * Should insert hooked blocks into registered patterns.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::get_all_registered
+	 */
+	public function test_get_all_registered_includes_hooked_blocks() {
+		register_block_type(
+			'tests/my-block',
+			array(
+				'block_hooks' => array(
+					'core/paragraph' => 'after',
+				),
+			)
+		);
+
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$pattern_two = array(
+			'title'   => 'Pattern Two',
+			'content' => '<!-- wp:paragraph --><p>Two</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/two', $pattern_two );
+
+		$pattern_three = array(
+			'title'   => 'Pattern Three',
+			'content' => '<!-- wp:paragraph --><p>Three</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/three', $pattern_three );
+
+		$pattern_one['name']       = 'test/one';
+		$pattern_two['name']       = 'test/two';
+		$pattern_two['content']   .= '<!-- wp:tests/my-block /-->';
+		$pattern_three['name']     = 'test/three';
+		$pattern_three['content'] .= '<!-- wp:tests/my-block /-->';
+
+		$expected = array(
+			$pattern_one,
+			$pattern_two,
+			$pattern_three,
+		);
+
+		$registered = $this->registry->get_all_registered();
+		$this->assertSame( $expected, $registered );
+	}
+
+	/**
+	 * Should insert hooked blocks into registered patterns.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::get_registered
+	 */
+	public function test_get_registered_includes_hooked_blocks() {
+		register_block_type(
+			'tests/my-block',
+			array(
+				'block_hooks' => array(
+					'core/heading' => 'before',
+				),
+			)
+		);
+
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$pattern_two = array(
+			'title'   => 'Pattern Two',
+			'content' => '<!-- wp:paragraph --><p>Two</p><!-- /wp:paragraph -->',
+		);
+		$this->registry->register( 'test/two', $pattern_two );
+
+		$pattern_one['name']    = 'test/one';
+		$pattern_one['content'] = '<!-- wp:tests/my-block /-->' . $pattern_one['content'];
+
+		$pattern = $this->registry->get_registered( 'test/one' );
+		$this->assertSame( $pattern_one, $pattern );
+	}
+
+	/**
+	 * Should return false for pattern that's not registered.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::is_registered
+	 */
+	public function test_is_registered_for_unknown_pattern() {
+		$pattern = $this->registry->is_registered( 'test/one' );
+		$this->assertFalse( $pattern );
+	}
+
+	/**
+	 * Should return true if pattern is registered.
+	 *
+	 * @ticket 59476
+	 *
+	 * @covers WP_Block_Patterns_Registry::register
+	 * @covers WP_Block_Patterns_Registry::is_registered
+	 */
+	public function test_is_registered_for_known_pattern() {
+		$pattern_one = array(
+			'title'   => 'Pattern One',
+			'content' => '<!-- wp:heading {"level":1} --><h1>One</h1><!-- /wp:heading -->',
+		);
+		$this->registry->register( 'test/one', $pattern_one );
+
+		$result = $this->registry->is_registered( 'test/one' );
+		$this->assertTrue( $result );
+	}
+}