diff --git a/plugins/woocommerce/changelog/add-add-block-to-block-template b/plugins/woocommerce/changelog/add-add-block-to-block-template
new file mode 100644
index 00000000000..f0994ad24c5
--- /dev/null
+++ b/plugins/woocommerce/changelog/add-add-block-to-block-template
@@ -0,0 +1,4 @@
+Significance: minor
+Type: add
+
+API for block-based templates.
diff --git a/plugins/woocommerce/src/Admin/BlockTemplates/BlockContainerInterface.php b/plugins/woocommerce/src/Admin/BlockTemplates/BlockContainerInterface.php
new file mode 100644
index 00000000000..7c221b6e4f6
--- /dev/null
+++ b/plugins/woocommerce/src/Admin/BlockTemplates/BlockContainerInterface.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Automattic\WooCommerce\Admin\BlockTemplates;
+
+/**
+ * Interface for block containers.
+ */
+interface BlockContainerInterface extends BlockInterface, ContainerInterface {}
diff --git a/plugins/woocommerce/src/Admin/BlockTemplates/BlockInterface.php b/plugins/woocommerce/src/Admin/BlockTemplates/BlockInterface.php
new file mode 100644
index 00000000000..9d22c1a464b
--- /dev/null
+++ b/plugins/woocommerce/src/Admin/BlockTemplates/BlockInterface.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace Automattic\WooCommerce\Admin\BlockTemplates;
+
+/**
+ * Interface for block configuration used to specify blocks in BlockTemplate.
+ */
+interface BlockInterface {
+	/**
+	 * Key for the block name in the block configuration.
+	 */
+	public const NAME_KEY = 'blockName';
+
+	/**
+	 * Key for the block ID in the block configuration.
+	 */
+	public const ID_KEY = 'id';
+
+	/**
+	 * Key for the internal order in the block configuration.
+	 */
+	public const ORDER_KEY = 'order';
+
+	/**
+	 * Key for the block attributes in the block configuration.
+	 */
+	public const ATTRIBUTES_KEY = 'attributes';
+
+	/**
+	 * Get the block name.
+	 */
+	public function get_name(): string;
+
+	/**
+	 * Get the block ID.
+	 */
+	public function get_id(): string;
+
+	/**
+	 * Get the block order.
+	 */
+	public function get_order(): int;
+
+	/**
+	 * Set the block order.
+	 *
+	 * @param int $order The block order.
+	 */
+	public function set_order( int $order );
+
+	/**
+	 * Get the block attributes.
+	 */
+	public function get_attributes(): array;
+
+	/**
+	 * Set the block attributes.
+	 *
+	 * @param array $attributes The block attributes.
+	 */
+	public function set_attributes( array $attributes );
+
+	/**
+	 * Get the parent container that the block belongs to.
+	 */
+	public function &get_parent(): ?ContainerInterface;
+
+	/**
+	 * Get the root template that the block belongs to.
+	 */
+	public function &get_root_template(): BlockTemplateInterface;
+
+	/**
+	 * Get the block configuration as a formatted template.
+	 *
+	 * @return array The block configuration as a formatted template.
+	 */
+	public function get_formatted_template(): array;
+}
diff --git a/plugins/woocommerce/src/Admin/BlockTemplates/BlockTemplateInterface.php b/plugins/woocommerce/src/Admin/BlockTemplates/BlockTemplateInterface.php
new file mode 100644
index 00000000000..b757c5947b2
--- /dev/null
+++ b/plugins/woocommerce/src/Admin/BlockTemplates/BlockTemplateInterface.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Automattic\WooCommerce\Admin\BlockTemplates;
+
+/**
+ * Interface for block-based template.
+ */
+interface BlockTemplateInterface extends ContainerInterface {
+	/**
+	 * Get a block by ID.
+	 *
+	 * @param string $block_id The block ID.
+	 */
+	public function get_block( string $block_id ): ?BlockInterface;
+
+	/**
+	 * Generate a block ID based on a base.
+	 *
+	 * @param string $id_base The base to use when generating an ID.
+	 * @return string
+	 */
+	public function generate_block_id( string $id_base ): string;
+}
diff --git a/plugins/woocommerce/src/Admin/BlockTemplates/ContainerInterface.php b/plugins/woocommerce/src/Admin/BlockTemplates/ContainerInterface.php
new file mode 100644
index 00000000000..5656fe4e9f6
--- /dev/null
+++ b/plugins/woocommerce/src/Admin/BlockTemplates/ContainerInterface.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Automattic\WooCommerce\Admin\BlockTemplates;
+
+/**
+ * Interface for block containers.
+ */
+interface ContainerInterface {
+	/**
+	 * Get the root template that the block belongs to.
+	 */
+	public function &get_root_template(): BlockTemplateInterface;
+
+	/**
+	 * Get the block configuration as a formatted template.
+	 */
+	public function get_formatted_template(): array;
+}
diff --git a/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlock.php b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlock.php
new file mode 100644
index 00000000000..54a21323ce0
--- /dev/null
+++ b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlock.php
@@ -0,0 +1,189 @@
+<?php
+
+namespace Automattic\WooCommerce\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\ContainerInterface;
+
+/**
+ * Block configuration used to specify blocks in BlockTemplate.
+ */
+class AbstractBlock implements BlockInterface {
+	/**
+	 * The block name.
+	 *
+	 * @var string
+	 */
+	private $name;
+
+	/**
+	 * The block ID.
+	 *
+	 * @var string
+	 */
+	private $id;
+
+	/**
+	 * The block order.
+	 *
+	 * @var int
+	 */
+	private $order = 10;
+
+	/**
+	 * The block attributes.
+	 *
+	 * @var array
+	 */
+	private $attributes = [];
+
+	/**
+	 * The block template that this block belongs to.
+	 *
+	 * @var BlockTemplate
+	 */
+	private $root_template;
+
+	/**
+	 * The parent container.
+	 *
+	 * @var ContainerInterface
+	 */
+	private $parent;
+
+	/**
+	 * Block constructor.
+	 *
+	 * @param array                        $config The block configuration.
+	 * @param BlockTemplateInterface       $root_template The block template that this block belongs to.
+	 * @param BlockContainerInterface|null $parent The parent block container.
+	 *
+	 * @throws \ValueError If the block configuration is invalid.
+	 * @throws \ValueError If the parent block container does not belong to the same template as the block.
+	 */
+	public function __construct( array $config, BlockTemplateInterface &$root_template, ContainerInterface &$parent = null ) {
+		$this->validate( $config, $root_template, $parent );
+
+		$this->root_template = $root_template;
+		$this->parent        = is_null( $parent ) ? $root_template : $parent;
+
+		$this->name = $config[ self::NAME_KEY ];
+
+		if ( ! isset( $config[ self::ID_KEY ] ) ) {
+			$this->id = $this->root_template->generate_block_id( $this->get_name() );
+		} else {
+			$this->id = $config[ self::ID_KEY ];
+		}
+
+		if ( isset( $config[ self::ORDER_KEY ] ) ) {
+			$this->order = $config[ self::ORDER_KEY ];
+		}
+
+		if ( isset( $config[ self::ATTRIBUTES_KEY ] ) ) {
+			$this->attributes = $config[ self::ATTRIBUTES_KEY ];
+		}
+	}
+
+	/**
+	 * Validate block configuration.
+	 *
+	 * @param array                   $config The block configuration.
+	 * @param BlockTemplateInterface  $root_template The block template that this block belongs to.
+	 * @param ContainerInterface|null $parent The parent block container.
+	 *
+	 * @throws \ValueError If the block configuration is invalid.
+	 * @throws \ValueError If the parent block container does not belong to the same template as the block.
+	 */
+	protected function validate( array $config, BlockTemplateInterface &$root_template, ContainerInterface &$parent = null ) {
+		if ( isset( $parent ) && ( $parent->get_root_template() !== $root_template ) ) {
+			throw new \ValueError( 'The parent block must belong to the same template as the block.' );
+		}
+
+		if ( ! isset( $config[ self::NAME_KEY ] ) || ! is_string( $config[ self::NAME_KEY ] ) ) {
+			throw new \ValueError( 'The block name must be specified.' );
+		}
+
+		if ( isset( $config[ self::ORDER_KEY ] ) && ! is_int( $config[ self::ORDER_KEY ] ) ) {
+			throw new \ValueError( 'The block order must be an integer.' );
+		}
+
+		if ( isset( $config[ self::ATTRIBUTES_KEY ] ) && ! is_array( $config[ self::ATTRIBUTES_KEY ] ) ) {
+			throw new \ValueError( 'The block attributes must be an array.' );
+		}
+	}
+
+	/**
+	 * Get the block name.
+	 */
+	public function get_name(): string {
+		return $this->name;
+	}
+
+	/**
+	 * Get the block ID.
+	 */
+	public function get_id(): string {
+		return $this->id;
+	}
+
+	/**
+	 * Get the block order.
+	 */
+	public function get_order(): int {
+		return $this->order;
+	}
+
+	/**
+	 * Set the block order.
+	 *
+	 * @param int $order The block order.
+	 */
+	public function set_order( int $order ) {
+		$this->order = $order;
+	}
+
+	/**
+	 * Get the block attributes.
+	 */
+	public function get_attributes(): array {
+		return $this->attributes;
+	}
+
+	/**
+	 * Set the block attributes.
+	 *
+	 * @param array $attributes The block attributes.
+	 */
+	public function set_attributes( array $attributes ) {
+		$this->attributes = $attributes;
+	}
+
+	/**
+	 * Get the template that this block belongs to.
+	 */
+	public function &get_root_template(): BlockTemplateInterface {
+		return $this->root_template;
+	}
+
+	/**
+	 * Get the parent block container.
+	 */
+	public function &get_parent(): ContainerInterface {
+		return $this->parent;
+	}
+
+	/**
+	 * Get the block configuration as a formatted template.
+	 *
+	 * @return array The block configuration as a formatted template.
+	 */
+	public function get_formatted_template(): array {
+		$arr = [
+			$this->get_name(),
+			$this->get_attributes(),
+		];
+
+		return $arr;
+	}
+}
diff --git a/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlockTemplate.php b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlockTemplate.php
new file mode 100644
index 00000000000..290c2cc7947
--- /dev/null
+++ b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/AbstractBlockTemplate.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace Automattic\WooCommerce\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\ContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+/**
+ * Block template class.
+ */
+abstract class AbstractBlockTemplate implements BlockTemplateInterface {
+	use BlockContainerTrait;
+
+	/**
+	 * The block cache.
+	 *
+	 * @var BlockInterface[]
+	 */
+	private $block_cache = [];
+
+	/**
+	 * Get a block by ID.
+	 *
+	 * @param string $block_id The block ID.
+	 */
+	public function get_block( string $block_id ): ?BlockInterface {
+		return $this->block_cache[ $block_id ] ?? null;
+	}
+
+	/**
+	 * Caches a block in the template. This is an internal method and should not be called directly
+	 * except for classes that implement BlockContainerInterface, in their add_block() method.
+	 *
+	 * @param BlockInterface $block The block to cache.
+	 *
+	 * @throws \ValueError If a block with the specified ID already exists in the template.
+	 * @throws \ValueError If the block template that the block belongs to is not this template.
+	 *
+	 * @ignore
+	 */
+	public function cache_block( BlockInterface &$block ) {
+		$id = $block->get_id();
+
+		if ( isset( $this->block_cache[ $id ] ) ) {
+			throw new \ValueError( 'A block with the specified ID already exists in the template.' );
+		}
+
+		if ( $block->get_root_template() !== $this ) {
+			throw new \ValueError( 'The block template that the block belongs to must be the same as this template.' );
+		}
+
+		$this->block_cache[ $id ] = $block;
+	}
+
+	/**
+	 * Generate a block ID based on a base.
+	 *
+	 * @param string $id_base The base to use when generating an ID.
+	 * @return string
+	 */
+	public function generate_block_id( string $id_base ): string {
+		$instance_count = 0;
+
+		do {
+			$instance_count++;
+			$block_id = $id_base . '-' . $instance_count;
+		} while ( isset( $this->block_cache[ $block_id ] ) );
+
+		return $block_id;
+	}
+
+	/**
+	 * Get the root template.
+	 */
+	public function &get_root_template(): BlockTemplateInterface {
+		return $this;
+	}
+
+	/**
+	 * Get the inner blocks as a formatted template.
+	 */
+	public function get_formatted_template(): array {
+		$inner_blocks = $this->get_inner_blocks_sorted_by_order();
+
+		$inner_blocks_formatted_template = array_map(
+			function( Block $block ) {
+				return $block->get_formatted_template();
+			},
+			$inner_blocks
+		);
+
+		return $inner_blocks_formatted_template;
+	}
+}
diff --git a/plugins/woocommerce/src/Internal/Admin/BlockTemplates/Block.php b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/Block.php
new file mode 100644
index 00000000000..bdd2c977c03
--- /dev/null
+++ b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/Block.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace Automattic\WooCommerce\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+/**
+ * Generic block with container properties to be used in BlockTemplate.
+ */
+class Block extends AbstractBlock implements BlockContainerInterface {
+	use BlockContainerTrait;
+
+	/**
+	 * Get the block configuration as a formatted template.
+	 *
+	 * @return array The block configuration as a formatted template.
+	 */
+	public function get_formatted_template(): array {
+		$arr = [
+			$this->get_name(),
+			$this->get_attributes(),
+		];
+
+		$inner_blocks = $this->get_inner_blocks_sorted_by_order();
+
+		if ( ! empty( $inner_blocks ) ) {
+			$arr[] = array_map(
+				function( BlockInterface $block ) {
+					return $block->get_formatted_template();
+				},
+				$inner_blocks
+			);
+		}
+
+		return $arr;
+	}
+
+	/**
+	 * Add an inner block to this block.
+	 *
+	 * @param array $block_config The block data.
+	 */
+	public function &add_block( array $block_config ): BlockInterface {
+		$block = new Block( $block_config, $this->get_root_template(), $this );
+		return $this->add_inner_block( $block );
+	}
+}
diff --git a/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockContainerTrait.php b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockContainerTrait.php
new file mode 100644
index 00000000000..731bef7cf4d
--- /dev/null
+++ b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockContainerTrait.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace Automattic\WooCommerce\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+
+/**
+ * Trait for block containers.
+ */
+trait BlockContainerTrait {
+	/**
+	 * The inner blocks.
+	 *
+	 * @var BlockInterface[]
+	 */
+	private $inner_blocks = [];
+
+	// phpcs doesn't take into account exceptions thrown by called methods.
+	// phpcs:disable Squiz.Commenting.FunctionCommentThrowTag.WrongNumber
+
+	/**
+	 * Add a block to the block container.
+	 *
+	 * @param BlockInterface $block The block.
+	 *
+	 * @throws \ValueError If the block configuration is invalid.
+	 * @throws \ValueError If a block with the specified ID already exists in the template.
+	 * @throws \UnexpectedValueException If the block container is not the parent of the block.
+	 */
+	protected function &add_inner_block( BlockInterface $block ): BlockInterface {
+		if ( ! $block instanceof BlockInterface ) {
+			throw new \UnexpectedValueException( 'The block must return an instance of BlockInterface.' );
+		}
+
+		if ( $block->get_parent() !== $this ) {
+			throw new \UnexpectedValueException( 'The block container is not the parent of the block.' );
+		}
+
+		$root_template = $block->get_root_template();
+		$root_template->cache_block( $block );
+		$this->inner_blocks[] = &$block;
+		return $block;
+	}
+
+	// phpcs:enable Squiz.Commenting.FunctionCommentThrowTag.WrongNumber
+
+	/**
+	 * Get the inner blocks sorted by order.
+	 */
+	private function get_inner_blocks_sorted_by_order(): array {
+		$sorted_inner_blocks = $this->inner_blocks;
+
+		usort(
+			$sorted_inner_blocks,
+			function( Block $a, Block $b ) {
+				return $a->get_order() <=> $b->get_order();
+			}
+		);
+
+		return $sorted_inner_blocks;
+	}
+
+	/**
+	 * Get the inner blocks as a formatted template.
+	 */
+	public function get_formatted_template(): array {
+		$arr = [
+			$this->get_name(),
+			$this->get_attributes(),
+		];
+
+		$inner_blocks = $this->get_inner_blocks_sorted_by_order();
+
+		if ( ! empty( $inner_blocks ) ) {
+			$arr[] = array_map(
+				function( BlockInterface $block ) {
+					return $block->get_formatted_template();
+				},
+				$inner_blocks
+			);
+		}
+
+		return $arr;
+	}
+}
diff --git a/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockTemplate.php b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockTemplate.php
new file mode 100644
index 00000000000..16eed6c32e7
--- /dev/null
+++ b/plugins/woocommerce/src/Internal/Admin/BlockTemplates/BlockTemplate.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Automattic\WooCommerce\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\ContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+/**
+ * Block template class.
+ */
+class BlockTemplate extends AbstractBlockTemplate {
+	/**
+	 * Generate a block ID based on a base.
+	 *
+	 * @param array $block_config The block data.
+	 */
+	public function add_block( array $block_config ): BlockInterface {
+		$block = new Block( $block_config, $this->get_root_template(), $this );
+		return $this->add_inner_block( $block );
+	}
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTemplateTest.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTemplateTest.php
new file mode 100644
index 00000000000..4b156d793d6
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTemplateTest.php
@@ -0,0 +1,367 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\BlockTemplate;
+
+use WC_Unit_Test_Case;
+
+/**
+ * Tests for the BlockTemplate class.
+ */
+class BlockTemplateTest extends WC_Unit_Test_Case {
+	/**
+	 * Test generating a block ID.
+	 */
+	public function test_generate_block_id() {
+		$template = new BlockTemplate();
+
+		$this->assertSame( 'test-block-id-1', $template->generate_block_id( 'test-block-id' ) );
+	}
+
+	/**
+	 * Test adding a block.
+	 */
+	public function test_add_block() {
+		$template = new BlockTemplate();
+
+		$block = $template->add_block(
+			[
+				'id'        => 'test-block-id',
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$this->assertSame( $block, $template->get_block( 'test-block-id' ) );
+	}
+
+	/**
+	 * Test adding a block throws an exception if a block with the same ID already exists.
+	 */
+	public function test_add_block_throws_exception_if_block_with_same_id_already_exists() {
+		$template = new BlockTemplate();
+
+		$template->add_block(
+			[
+				'id'        => 'test-block-id',
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$this->expectException( \ValueError::class );
+
+		$template->add_block(
+			[
+				'id'        => 'test-block-id',
+				'blockName' => 'test-block-name',
+			]
+		);
+	}
+
+	/**
+	 * Test adding a block generates an ID if one is not provided.
+	 */
+	public function test_add_block_generates_id_if_not_provided() {
+		$template = new BlockTemplate();
+
+		$block = $template->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$this->assertSame( 'test-block-name-1', $block->get_id() );
+	}
+
+	/**
+	 * Test getting a block by ID returns null if the block does not exist.
+	 */
+	public function test_get_block_returns_null_if_block_does_not_exist() {
+		$template = new BlockTemplate();
+
+		$this->assertNull( $template->get_block( 'test-block-id' ) );
+	}
+
+	/**
+	 * Test getting a block by ID returns a reference to the block.
+	 */
+	public function test_get_block_returns_reference() {
+		$template = new BlockTemplate();
+
+		$template->add_block(
+			[
+				'id'        => 'test-block-id',
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$block = $template->get_block( 'test-block-id' );
+
+		$block->set_order( 23 );
+
+		$this->assertSame( 23, $template->get_block( 'test-block-id' )->get_order() );
+	}
+
+	/**
+	 * Test that the formatted template representation of a block template is correct.
+	 */
+	public function test_get_formatted_template() {
+		$template = new BlockTemplate();
+
+		$template->add_block(
+			[
+				'blockName'  => 'test-block-name-c',
+				'order'      => 100,
+				'attributes' => [
+					'attr-c1' => 'value-c1',
+					'attr-c2' => 'value-c2',
+				],
+			]
+		);
+
+		$block_b = $template->add_block(
+			[
+				'blockName'  => 'test-block-name-b',
+				'order'      => 50,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$template->add_block(
+			[
+				'blockName'  => 'test-block-name-a',
+				'order'      => 10,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName'  => 'test-block-name-2',
+				'order'      => 20,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName'  => 'test-block-name-1',
+				'order'      => 10,
+				'attributes' => [
+					'attr-3' => 'value-3',
+					'attr-4' => 'value-4',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName' => 'test-block-name-3',
+				'order'     => 30,
+			]
+		);
+
+		$this->assertSame(
+			[
+				[
+					'test-block-name-a',
+					[
+						'attr-1' => 'value-1',
+						'attr-2' => 'value-2',
+					],
+				],
+				[
+					'test-block-name-b',
+					[
+						'attr-1' => 'value-1',
+						'attr-2' => 'value-2',
+					],
+					[
+						[
+							'test-block-name-1',
+							[
+								'attr-3' => 'value-3',
+								'attr-4' => 'value-4',
+							],
+						],
+						[
+							'test-block-name-2',
+							[
+								'attr-1' => 'value-1',
+								'attr-2' => 'value-2',
+							],
+						],
+						[
+							'test-block-name-3',
+							[],
+						],
+					],
+				],
+				[
+					'test-block-name-c',
+					[
+						'attr-c1' => 'value-c1',
+						'attr-c2' => 'value-c2',
+					],
+				],
+			],
+			$template->get_formatted_template(),
+			'Failed asserting that the block is converted to a simple array correctly.'
+		);
+	}
+
+	/**
+	 * Test that inserting a block to a parent in the template works.
+	 */
+	public function test_inserting_block_by_parent_id() {
+		$template = new BlockTemplate();
+
+		$template->add_block(
+			[
+				'blockName'  => 'test-block-name-c',
+				'order'      => 100,
+				'attributes' => [
+					'attr-c1' => 'value-c1',
+					'attr-c2' => 'value-c2',
+				],
+			]
+		);
+
+		$block_b = $template->add_block(
+			[
+				'id'         => 'b',
+				'blockName'  => 'test-block-name-b',
+				'order'      => 50,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$template->add_block(
+			[
+				'id'         => 'a',
+				'blockName'  => 'test-block-name-a',
+				'order'      => 10,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName'  => 'test-block-name-2',
+				'order'      => 20,
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName'  => 'test-block-name-1',
+				'order'      => 10,
+				'attributes' => [
+					'attr-3' => 'value-3',
+					'attr-4' => 'value-4',
+				],
+			]
+		);
+
+		$block_b->add_block(
+			[
+				'blockName' => 'test-block-name-3',
+				'order'     => 30,
+			]
+		);
+
+		$block_to_insert_in = $template->get_block( 'a' );
+
+		$block_to_insert_in->add_block(
+			[
+				'blockName' => 'inserted-block',
+			]
+		);
+
+		$another_block_to_insert_in = $template->get_block( 'b' );
+
+		$another_block_to_insert_in->add_block(
+			[
+				'blockName' => 'another-inserted-block',
+				'order'     => 15,
+			]
+		);
+
+		$this->assertSame(
+			[
+				[
+					'test-block-name-a',
+					[
+						'attr-1' => 'value-1',
+						'attr-2' => 'value-2',
+					],
+					[
+						[
+							'inserted-block',
+							[],
+						],
+					],
+				],
+				[
+					'test-block-name-b',
+					[
+						'attr-1' => 'value-1',
+						'attr-2' => 'value-2',
+					],
+					[
+						[
+							'test-block-name-1',
+							[
+								'attr-3' => 'value-3',
+								'attr-4' => 'value-4',
+							],
+						],
+						[
+							'another-inserted-block',
+							[],
+						],
+						[
+							'test-block-name-2',
+							[
+								'attr-1' => 'value-1',
+								'attr-2' => 'value-2',
+							],
+						],
+						[
+							'test-block-name-3',
+							[],
+						],
+					],
+				],
+				[
+					'test-block-name-c',
+					[
+						'attr-c1' => 'value-c1',
+						'attr-c2' => 'value-c2',
+					],
+				],
+			],
+			$template->get_formatted_template(),
+			'Failed asserting that the template is converted to a formatted template correctly.'
+		);
+	}
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTest.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTest.php
new file mode 100644
index 00000000000..79f5c054e1c
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/BlockTest.php
@@ -0,0 +1,306 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\Block;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\BlockTemplate;
+
+use WC_Unit_Test_Case;
+
+/**
+ * Tests for the Block class.
+ */
+class BlockTest extends WC_Unit_Test_Case {
+	/**
+	 * Test that the block name is required when creating a block.
+	 */
+	public function test_name_is_required() {
+		$template = new BlockTemplate();
+
+		$this->expectException( \ValueError::class );
+
+		new Block( [], $template );
+	}
+
+	/**
+	 * Test that an ID is generated if not provided when creating a block.
+	 */
+	public function test_id_is_generated_if_not_provided() {
+		$template = new BlockTemplate();
+
+		$block = new Block(
+			[
+				'blockName' => 'test-block-name',
+			],
+			$template
+		);
+
+		$this->assertSame( 'test-block-name-1', $block->get_id() );
+	}
+
+	/**
+	 * Test that setting a parent from a different template is prevented.
+	 */
+	public function test_parent_from_different_template_throws_exception() {
+		$template   = new BlockTemplate();
+		$template_2 = new BlockTemplate();
+
+		$parent = new Block(
+			[
+				'blockName' => 'test-block-parent-name',
+			],
+			$template_2
+		);
+
+		$this->expectException( \ValueError::class );
+
+		new Block(
+			[
+				'blockName' => 'test-block-name',
+			],
+			$template,
+			$parent
+		);
+	}
+
+	/**
+	 * Test that adding a block to a block sets the parent and root template correctly
+	 * and that the block is added to the root template.
+	 */
+	public function test_add_block() {
+		$template = new BlockTemplate();
+
+		$block = $template->add_block(
+			[
+				'id'        => 'test-block-id',
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$child_block = $block->add_block(
+			[
+				'id'        => 'test-block-id-2',
+				'blockName' => 'test-block-name-2',
+			]
+		);
+
+		$this->assertSame(
+			$child_block->get_root_template(),
+			$block->get_root_template(),
+			'Failed asserting that the child block has the same root template as the parent block.'
+		);
+
+		$this->assertSame(
+			$block,
+			$child_block->get_parent(),
+			'Failed asserting that the child block\'s parent is the block it was added to.'
+		);
+		$this->assertSame(
+			$child_block,
+			$template->get_block( 'test-block-id-2' ),
+			'Failed asserting that the child block is in the root template.'
+		);
+	}
+
+	/**
+	 * Test that adding nested blocks sets the parent and root template correctly.
+	 */
+	public function test_nested_add_block() {
+		$block_template = new BlockTemplate();
+
+		$block = $block_template->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$child_block_1 = $block->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$grandchild_block = $child_block_1->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$this->assertSame(
+			$block_template,
+			$grandchild_block->get_root_template(),
+			'Failed asserting that the grandchild block has the same root template.'
+		);
+
+		$grandchild_parent = $grandchild_block->get_parent();
+
+		$this->assertSame(
+			$child_block_1,
+			$grandchild_parent,
+			'Failed asserting that the grandchild block\'s parent is the block it was added to.'
+		);
+
+		$this->assertInstanceOf(
+			BlockContainerInterface::class,
+			$grandchild_parent,
+			'Failed asserting that the grandchild block\'s parent is a BlockContainerInterface instance.'
+		);
+
+		$this->assertSame(
+			$block,
+			$grandchild_parent->get_parent(),
+			'Failed asserting that the grandchild block\'s grandparent is correct.'
+		);
+	}
+
+	/**
+	 * Test that getting the block as a formatted template is structured correctly.
+	 */
+	public function test_get_formatted_template() {
+		$template = new BlockTemplate();
+
+		$block = $template->add_block(
+			[
+				'id'         => 'test-block-id',
+				'blockName'  => 'test-block-name',
+				'attributes' => [
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+			]
+		);
+
+		$block->add_block(
+			[
+				'id'         => 'test-block-id-2',
+				'blockName'  => 'test-block-name-2',
+				'attributes' => [
+					'attr-3' => 'value-3',
+					'attr-4' => 'value-4',
+				],
+			]
+		);
+
+		$block->add_block(
+			[
+				'id'        => 'test-block-id-3',
+				'blockName' => 'test-block-name-3',
+			]
+		);
+
+		$formatted_template = $block->get_formatted_template();
+
+		$this->assertSame(
+			[
+				'test-block-name',
+				[
+					'attr-1' => 'value-1',
+					'attr-2' => 'value-2',
+				],
+				[
+					[
+						'test-block-name-2',
+						[
+							'attr-3' => 'value-3',
+							'attr-4' => 'value-4',
+						],
+					],
+					[
+						'test-block-name-3',
+						[],
+					],
+				],
+			],
+			$formatted_template,
+			'Failed asserting that the block is converted to a formatted template correctly.'
+		);
+	}
+
+	/**
+	 * Test that getting the inner blocks as a sorted formatted template is ordered correctly.
+	 */
+	public function test_get_formatted_template_with_sorting() {
+		$template = new BlockTemplate();
+
+		$block = $template->add_block(
+			[
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'five',
+				'order'     => 5,
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'three',
+				'order'     => 3,
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'one',
+				'order'     => 1,
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'four',
+				'order'     => 4,
+			]
+		);
+
+		$block->add_block(
+			[
+				'blockName' => 'two',
+				'order'     => 2,
+			]
+		);
+
+		$this->assertSame(
+			[
+				'test-block-name',
+				[],
+				[
+					[
+						'one',
+						[],
+					],
+					[
+						'two',
+						[],
+					],
+					[
+						'three',
+						[],
+					],
+					[
+						'four',
+						[],
+					],
+					[
+						'five',
+						[],
+					],
+				],
+			],
+			$block->get_formatted_template(),
+			'Failed asserting that the inner blocks are sorted by order.'
+		);
+	}
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlock.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlock.php
new file mode 100644
index 00000000000..46f524aaa3f
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlock.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\AbstractBlock;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\Block;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\BlockContainerTrait;
+
+/**
+ * Custom block class for testing.
+ */
+class CustomBlock extends AbstractBlock implements CustomBlockInterface {
+	use BlockContainerTrait;
+
+	/**
+	 * Custom method.
+	 */
+	public function add_custom_inner_block(): BlockInterface {
+		$block = new Block(
+			[
+				'blockName' => 'custom-inner-block',
+			],
+			$this->get_root_template(),
+			$this
+		);
+
+		$this->add_inner_block( $block );
+
+		return $block;
+	}
+}
+
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockInterface.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockInterface.php
new file mode 100644
index 00000000000..dbaf133a8c8
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockInterface.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+
+interface CustomBlockInterface extends BlockContainerInterface {
+	/**
+	 * Adds a method to insert a specific custom inner block.
+	 */
+	public function add_custom_inner_block(): BlockInterface;
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplate.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplate.php
new file mode 100644
index 00000000000..a8bb953497f
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplate.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockInterface;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\AbstractBlockTemplate;
+
+/**
+ * Custom block template class.
+ */
+class CustomBlockTemplate extends AbstractBlockTemplate {
+	/**
+	 * Add a custom block type to this template.
+	 *
+	 * @param array $block_config The block data.
+	 */
+	public function add_custom_block( array $block_config ): BlockInterface {
+		$block = new CustomBlock( $block_config, $this->get_root_template(), $this );
+		return $this->add_inner_block( $block );
+	}
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplateTest.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplateTest.php
new file mode 100644
index 00000000000..6c6d9d86860
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTemplateTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\Block;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\BlockTemplate;
+
+use WC_Unit_Test_Case;
+
+/**
+ * Tests for the CustomBlockTemplate class.
+ */
+class CustomBlockTemplateTest extends WC_Unit_Test_Case {
+	/**
+	 * Test that the add_block method does not exist by default on templates.
+	 */
+	public function test_add_block_does_not_exist() {
+		$template = new CustomBlockTemplate();
+		$this->assertFalse( method_exists( $template, 'add_block' ) );
+	}
+
+	/**
+	 * Test that a custom block inserter method inserts as expected.
+	 */
+	public function test_add_custom_block() {
+		$template = new CustomBlockTemplate();
+
+		$template->add_custom_block(
+			[
+				'id'        => 'test-block-name',
+				'blockName' => 'test-block-name',
+			]
+		);
+
+		$block = $template->get_block( 'test-block-name' );
+		$this->assertInstanceOf( CustomBlock::class, $block );
+	}
+}
diff --git a/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTest.php b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTest.php
new file mode 100644
index 00000000000..f6f81d52c31
--- /dev/null
+++ b/plugins/woocommerce/tests/php/src/Internal/Admin/BlockTemplates/CustomBlockTest.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Automattic\WooCommerce\Tests\Internal\Admin\BlockTemplates;
+
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockContainerInterface;
+use Automattic\WooCommerce\Admin\BlockTemplates\BlockTemplateInterface;
+
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\Block;
+use Automattic\WooCommerce\Internal\Admin\BlockTemplates\BlockTemplate;
+
+use WC_Unit_Test_Case;
+
+/**
+ * Tests for the CustomBlock class.
+ */
+class CustomBlockTest extends WC_Unit_Test_Case {
+	/**
+	 * Test that the add_block method does not exist by default on blocks.
+	 */
+	public function test_add_block_does_not_exist() {
+		$template = new BlockTemplate();
+		$block    = new CustomBlock(
+			[
+				'blockName' => 'test-block-name',
+			],
+			$template
+		);
+
+		$this->assertFalse( method_exists( $block, 'add_block' ) );
+	}
+
+	/**
+	 * Test that a custom block inserter method inserts as expected.
+	 */
+	public function test_add_custom_inner_block() {
+		$template = new BlockTemplate();
+		$block    = new CustomBlock(
+			[
+				'blockName' => 'test-block-name',
+			],
+			$template
+		);
+
+		$block->add_custom_inner_block();
+
+		$this->assertSame(
+			[
+				'test-block-name',
+				[],
+				[
+					[
+						'custom-inner-block',
+						[],
+					],
+				],
+			],
+			$block->get_formatted_template(),
+			'Failed asserting that the inner block was added'
+		);
+	}
+}