diff --git a/src/wp-includes/category-template.php b/src/wp-includes/category-template.php
index 9a2120c9e3..5fb7485332 100644
--- a/src/wp-includes/category-template.php
+++ b/src/wp-includes/category-template.php
@@ -532,7 +532,28 @@ function wp_list_categories( $args = '' ) {
 		}
 	} else {
 		if ( ! empty( $show_option_all ) ) {
-			$posts_page = ( 'page' == get_option( 'show_on_front' ) && get_option( 'page_for_posts' ) ) ? get_permalink( get_option( 'page_for_posts' ) ) : home_url( '/' );
+
+			$posts_page = '';
+
+			// For taxonomies that belong only to custom post types, point to a valid archive.
+			$taxonomy_object = get_taxonomy( $r['taxonomy'] );
+			if ( ! in_array( 'post', $taxonomy_object->object_type ) && ! in_array( 'page', $taxonomy_object->object_type ) ) {
+				foreach ( $taxonomy_object->object_type as $object_type ) {
+					$_object_type = get_post_type_object( $object_type );
+
+					// Grab the first one.
+					if ( ! empty( $_object_type->has_archive ) ) {
+						$posts_page = get_post_type_archive_link( $object_type );
+						break;
+					}
+				}
+			}
+
+			// Fallback for the 'All' link is the front page.
+			if ( ! $posts_page ) {
+				$posts_page = 'page' == get_option( 'show_on_front' ) && get_option( 'page_for_posts' ) ? get_permalink( get_option( 'page_for_posts' ) ) : home_url( '/' );
+			}
+
 			$posts_page = esc_url( $posts_page );
 			if ( 'list' == $r['style'] ) {
 				$output .= "<li class='cat-item-all'><a href='$posts_page'>$show_option_all</a></li>";
diff --git a/tests/phpunit/tests/category/wpListCategories.php b/tests/phpunit/tests/category/wpListCategories.php
index 55af2f484e..e2c041c90e 100644
--- a/tests/phpunit/tests/category/wpListCategories.php
+++ b/tests/phpunit/tests/category/wpListCategories.php
@@ -100,6 +100,96 @@ class Tests_Category_WpListCategories extends WP_UnitTestCase {
 		$this->assertContains( "<li class='cat-item-all'><a href='" . get_permalink( $p ) . "'>All</a></li>", $found );
 	}
 
+	/**
+	 * @ticket 21881
+	 */
+	public function test_show_option_all_link_should_link_to_post_type_archive_when_taxonomy_does_not_apply_to_posts() {
+		register_post_type( 'wptests_pt', array( 'has_archive' => true ) );
+		register_post_type( 'wptests_pt2', array( 'has_archive' => true ) );
+		register_taxonomy( 'wptests_tax', array( 'foo', 'wptests_pt', 'wptests_pt2' ) );
+
+		$terms = $this->factory->term->create_many( 2, array(
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'show_option_all' => 'All',
+			'hide_empty' => false,
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$pt_archive = get_post_type_archive_link( 'wptests_pt' );
+
+		$this->assertContains( "<li class='cat-item-all'><a href='" . $pt_archive . "'>All</a></li>", $found );
+	}
+
+	/**
+	 * @ticket 21881
+	 */
+	public function test_show_option_all_link_should_not_link_to_post_type_archive_if_has_archive_is_false() {
+		register_post_type( 'wptests_pt', array( 'has_archive' => false ) );
+		register_post_type( 'wptests_pt2', array( 'has_archive' => true ) );
+		register_taxonomy( 'wptests_tax', array( 'foo', 'wptests_pt', 'wptests_pt2' ) );
+
+		$terms = $this->factory->term->create_many( 2, array(
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'show_option_all' => 'All',
+			'hide_empty' => false,
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$pt_archive = get_post_type_archive_link( 'wptests_pt2' );
+
+		$this->assertContains( "<li class='cat-item-all'><a href='" . $pt_archive . "'>All</a></li>", $found );
+	}
+
+	public function test_show_option_all_link_should_link_to_post_archive_if_available() {
+		register_post_type( 'wptests_pt', array( 'has_archive' => true ) );
+		register_post_type( 'wptests_pt2', array( 'has_archive' => true ) );
+		register_taxonomy( 'wptests_tax', array( 'foo', 'wptests_pt', 'post', 'wptests_pt2' ) );
+
+		$terms = $this->factory->term->create_many( 2, array(
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'show_option_all' => 'All',
+			'hide_empty' => false,
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$url = home_url( '/' );
+
+		$this->assertContains( "<li class='cat-item-all'><a href='" . $url . "'>All</a></li>", $found );
+	}
+
+	public function test_show_option_all_link_should_link_to_post_archive_if_no_associated_post_types_have_archives() {
+		register_post_type( 'wptests_pt', array( 'has_archive' => false ) );
+		register_post_type( 'wptests_pt2', array( 'has_archive' => false ) );
+		register_taxonomy( 'wptests_tax', array( 'foo', 'wptests_pt', 'wptests_pt2' ) );
+
+		$terms = $this->factory->term->create_many( 2, array(
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'show_option_all' => 'All',
+			'hide_empty' => false,
+			'taxonomy' => 'wptests_tax',
+		) );
+
+		$url = home_url( '/' );
+
+		$this->assertContains( "<li class='cat-item-all'><a href='" . $url . "'>All</a></li>", $found );
+	}
+
 	public function list_cats_callback( $cat ) {
 		if ( 'Test Cat 1' === $cat ) {
 			return '';