diff --git a/lib/load.php b/lib/load.php
index 58e545b38a6f7..52567857fbba8 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -54,6 +54,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 
 require dirname( __FILE__ ) . '/blocks.php';
 require dirname( __FILE__ ) . '/templates.php';
+require dirname( __FILE__ ) . '/template-parts.php';
 require dirname( __FILE__ ) . '/template-loader.php';
 require dirname( __FILE__ ) . '/client-assets.php';
 require dirname( __FILE__ ) . '/block-directory.php';
diff --git a/lib/template-loader.php b/lib/template-loader.php
index 30ea5fae54f8e..7625a3bd7d35f 100644
--- a/lib/template-loader.php
+++ b/lib/template-loader.php
@@ -72,6 +72,40 @@ function gutenberg_override_query_template( $template, $type, array $templates =
 	return '';
 }
 
+/**
+ * Recursively traverses a block tree, creating auto drafts
+ * for any encountered template parts without a fixed post.
+ *
+ * @access private
+ *
+ * @param array $block The root block to start traversing from.
+ */
+function create_auto_draft_for_template_part_block( $block ) {
+	if ( 'core/template-part' === $block['blockName'] && ! isset( $block['attrs']['id'] ) ) {
+		$template_part_file_path =
+			get_stylesheet_directory() . '/block-template-parts/' . $block['attrs']['slug'] . '.html';
+		if ( ! file_exists( $template_part_file_path ) ) {
+			return;
+		}
+		wp_insert_post(
+			array(
+				'post_content' => file_get_contents( $template_part_file_path ),
+				'post_title'   => ucfirst( $block['attrs']['slug'] ),
+				'post_status'  => 'auto-draft',
+				'post_type'    => 'wp_template_part',
+				'post_name'    => $block['attrs']['slug'],
+				'meta_input'   => array(
+					'theme' => $block['attrs']['theme'],
+				),
+			)
+		);
+	}
+
+	foreach ( $block['innerBlocks'] as $inner_block ) {
+		create_auto_draft_for_template_part_block( $inner_block );
+	}
+}
+
 /**
  * Find the correct 'wp_template' post for the current hierarchy and return the path
  * to the canvas file that will render it.
@@ -147,6 +181,10 @@ function gutenberg_find_template( $template_file ) {
 				$current_template_post = get_post(
 					wp_insert_post( $current_template_post )
 				);
+
+				foreach ( parse_blocks( $current_template_post->post_content ) as $block ) {
+					create_auto_draft_for_template_part_block( $block );
+				}
 			} else {
 				$current_template_post = new WP_Post(
 					(object) $current_template_post
diff --git a/lib/template-parts.php b/lib/template-parts.php
new file mode 100644
index 0000000000000..e14b584ead3ad
--- /dev/null
+++ b/lib/template-parts.php
@@ -0,0 +1,118 @@
+<?php
+/**
+ * Block template part functions.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Registers block editor 'wp_template_part' post type.
+ */
+function gutenberg_register_template_part_post_type() {
+	if ( ! gutenberg_is_experiment_enabled( 'gutenberg-full-site-editing' ) ) {
+		return;
+	}
+
+	$labels = array(
+		'name'                  => __( 'Template Parts', 'gutenberg' ),
+		'singular_name'         => __( 'Template Part', 'gutenberg' ),
+		'menu_name'             => _x( 'Template Parts', 'Admin Menu text', 'gutenberg' ),
+		'add_new'               => _x( 'Add New', 'Template Part', 'gutenberg' ),
+		'add_new_item'          => __( 'Add New Template Part', 'gutenberg' ),
+		'new_item'              => __( 'New Template Part', 'gutenberg' ),
+		'edit_item'             => __( 'Edit Template Part', 'gutenberg' ),
+		'view_item'             => __( 'View Template Part', 'gutenberg' ),
+		'all_items'             => __( 'All Template Parts', 'gutenberg' ),
+		'search_items'          => __( 'Search Template Parts', 'gutenberg' ),
+		'parent_item_colon'     => __( 'Parent Template Part:', 'gutenberg' ),
+		'not_found'             => __( 'No template parts found.', 'gutenberg' ),
+		'not_found_in_trash'    => __( 'No template parts found in Trash.', 'gutenberg' ),
+		'archives'              => __( 'Template part archives', 'gutenberg' ),
+		'insert_into_item'      => __( 'Insert into template part', 'gutenberg' ),
+		'uploaded_to_this_item' => __( 'Uploaded to this template part', 'gutenberg' ),
+		'filter_items_list'     => __( 'Filter template parts list', 'gutenberg' ),
+		'items_list_navigation' => __( 'Template parts list navigation', 'gutenberg' ),
+		'items_list'            => __( 'Template parts list', 'gutenberg' ),
+	);
+
+	$args = array(
+		'labels'            => $labels,
+		'description'       => __( 'Template parts to include in your templates.', 'gutenberg' ),
+		'public'            => false,
+		'has_archive'       => false,
+		'show_ui'           => true,
+		'show_in_menu'      => 'themes.php',
+		'show_in_admin_bar' => false,
+		'show_in_rest'      => true,
+		'map_meta_cap'      => true,
+		'supports'          => array(
+			'title',
+			'slug',
+			'editor',
+			'revisions',
+		),
+	);
+
+	$meta_args = array(
+		'object_subtype' => 'wp_template_part',
+		'type'           => 'string',
+		'description'    => 'The theme that provided the template part, if any.',
+		'single'         => true,
+		'show_in_rest'   => true,
+	);
+
+	register_post_type( 'wp_template_part', $args );
+	register_meta( 'post', 'theme', $meta_args );
+}
+add_action( 'init', 'gutenberg_register_template_part_post_type' );
+
+/**
+ * Fixes the label of the 'wp_template_part' admin menu entry.
+ */
+function gutenberg_fix_template_part_admin_menu_entry() {
+	global $submenu;
+	if ( ! isset( $submenu['themes.php'] ) ) {
+		return;
+	}
+	$post_type = get_post_type_object( 'wp_template_part' );
+	if ( ! $post_type ) {
+		return;
+	}
+	foreach ( $submenu['themes.php'] as $key => $submenu_entry ) {
+		if ( $post_type->labels->all_items === $submenu['themes.php'][ $key ][0] ) {
+			$submenu['themes.php'][ $key ][0] = $post_type->labels->menu_name; // phpcs:ignore WordPress.WP.GlobalVariablesOverride
+			break;
+		}
+	}
+}
+add_action( 'admin_menu', 'gutenberg_fix_template_part_admin_menu_entry' );
+
+/**
+ * Filters the 'wp_template_part' post type columns in the admin list table.
+ *
+ * @param array $columns Columns to display.
+ * @return array Filtered $columns.
+ */
+function gutenberg_filter_template_part_list_table_columns( array $columns ) {
+	$columns['slug'] = __( 'Slug', 'gutenberg' );
+	if ( isset( $columns['date'] ) ) {
+		unset( $columns['date'] );
+	}
+	return $columns;
+}
+add_filter( 'manage_wp_template_part_posts_columns', 'gutenberg_filter_template_part_list_table_columns' );
+
+/**
+ * Renders column content for the 'wp_template_part' post type list table.
+ *
+ * @param string $column_name Column name to render.
+ * @param int    $post_id     Post ID.
+ */
+function gutenberg_render_template_part_list_table_column( $column_name, $post_id ) {
+	if ( 'slug' !== $column_name ) {
+		return;
+	}
+	$post = get_post( $post_id );
+	echo esc_html( $post->post_name );
+}
+add_action( 'manage_wp_template_part_posts_custom_column', 'gutenberg_render_template_part_list_table_column', 10, 2 );