diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
index 49e5c8d829..df8a3dcd6d 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
@@ -105,7 +105,7 @@ class WP_REST_Templates_Controller extends WP_REST_Controller {
 				// Excludes invalid directory name characters: `/:<>*?"|`.
 				'([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)',
 				// Matches the template name.
-				'[\/\w-]+'
+				'[\/\w%-]+'
 			),
 			array(
 				'args'   => array(
@@ -834,7 +834,7 @@ class WP_REST_Templates_Controller extends WP_REST_Controller {
 					'context'     => array( 'embed', 'view', 'edit' ),
 					'required'    => true,
 					'minLength'   => 1,
-					'pattern'     => '[a-zA-Z0-9_\-]+',
+					'pattern'     => '[a-zA-Z0-9_\%-]+',
 				),
 				'theme'          => array(
 					'description' => __( 'Theme identifier for the template.' ),
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/index.php b/tests/phpunit/data/themedir1/block-theme-non-latin/index.php
new file mode 100644
index 0000000000..589adcefcd
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/index.php
@@ -0,0 +1,4 @@
+<?php
+/**
+ * Block theme.
+ */
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/page-1.php b/tests/phpunit/data/themedir1/block-theme-non-latin/page-1.php
new file mode 100644
index 0000000000..eafbb1b6e8
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/page-1.php
@@ -0,0 +1,3 @@
+<?php
+
+echo 'PHP template for page with ID 1';
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/parts/small-header-τεστ.html b/tests/phpunit/data/themedir1/block-theme-non-latin/parts/small-header-τεστ.html
new file mode 100644
index 0000000000..5c18e98125
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/parts/small-header-τεστ.html
@@ -0,0 +1,3 @@
+<!-- wp:paragraph -->
+<p>Small Header Template Part</p>
+<!-- /wp:paragraph -->
\ No newline at end of file
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/parts/small-header-测试.html b/tests/phpunit/data/themedir1/block-theme-non-latin/parts/small-header-测试.html
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/style.css b/tests/phpunit/data/themedir1/block-theme-non-latin/style.css
new file mode 100644
index 0000000000..4de5f009a5
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/style.css
@@ -0,0 +1,7 @@
+/*
+Theme Name: Block Theme Non Latin
+Theme URI: https://wordpress.org/
+Description: Has different characters in theme directory name for testing purposes.
+Version: 0.0.1
+Text Domain: block-theme
+*/
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-τεστ.html b/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-τεστ.html
new file mode 100644
index 0000000000..ff8979cb4f
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-τεστ.html
@@ -0,0 +1,3 @@
+<!-- wp:paragraph -->
+<p>(τεστ) Page Template</p>
+<!-- /wp:paragraph -->
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-测试.html b/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-测试.html
new file mode 100644
index 0000000000..1aca9fe8ab
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/templates/page-测试.html
@@ -0,0 +1,3 @@
+<!-- wp:paragraph -->
+<p>(测试) Page Template</p>
+<!-- /wp:paragraph -->
diff --git a/tests/phpunit/data/themedir1/block-theme-non-latin/theme.json b/tests/phpunit/data/themedir1/block-theme-non-latin/theme.json
new file mode 100644
index 0000000000..f0c59a63ab
--- /dev/null
+++ b/tests/phpunit/data/themedir1/block-theme-non-latin/theme.json
@@ -0,0 +1,80 @@
+{
+	"version": 1,
+	"settings": {
+		"color": {
+			"palette": [
+				{
+					"slug": "light",
+					"name": "Light",
+					"color": "#f5f7f9"
+				},
+				{
+					"slug": "dark",
+					"name": "Dark",
+					"color": "#000"
+				}
+			],
+			"gradients": [
+				{
+					"name": "Custom gradient",
+					"gradient": "linear-gradient(135deg,rgba(0,0,0) 0%,rgb(0,0,0) 100%)",
+					"slug": "custom-gradient"
+				}
+			],
+			"custom": false,
+			"customGradient": false
+		},
+		"typography": {
+			"fontSizes": [
+				{
+					"name": "Custom",
+					"slug": "custom",
+					"size": "100px"
+				}
+			],
+			"customFontSize": false,
+			"customLineHeight": true
+		},
+		"spacing": {
+			"units": [
+				"rem"
+			],
+			"customPadding": true
+		},
+		"blocks": {
+			"core/paragraph": {
+				"color": {
+					"palette": [
+						{
+							"slug": "light",
+							"name": "Light",
+							"color": "#f5f7f9"
+						}
+					]
+				}
+			}
+		}
+	},
+	"customTemplates": [
+		{
+			"name": "page-τεστ",
+			"title": "Homepage template"
+		},
+		{
+			"name": "page-测试",
+			"title": "Homepage template"
+		}
+	],
+	"templateParts": [
+		{
+			"name": "small-header-τεστ",
+			"title": "Small Header",
+			"area": "header"
+		},
+		{
+			"name": "small-header-测试",
+			"title": "Small Header",
+			"area": "header"
+		},
+	]
+}
diff --git a/tests/phpunit/tests/rest-api/rest-schema-setup.php b/tests/phpunit/tests/rest-api/rest-schema-setup.php
index 9347f33256..7b8544d5e2 100644
--- a/tests/phpunit/tests/rest-api/rest-schema-setup.php
+++ b/tests/phpunit/tests/rest-api/rest-schema-setup.php
@@ -146,14 +146,14 @@ class WP_Test_REST_Schema_Initialization extends WP_Test_REST_TestCase {
 			'/wp/v2/settings',
 			'/wp/v2/template-parts',
 			'/wp/v2/template-parts/(?P<id>[\d]+)/autosaves',
-			'/wp/v2/template-parts/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w-]+)',
+			'/wp/v2/template-parts/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w%-]+)',
 			'/wp/v2/template-parts/(?P<parent>[\d]+)/autosaves/(?P<id>[\d]+)',
 			'/wp/v2/template-parts/(?P<parent>[\d]+)/revisions',
 			'/wp/v2/template-parts/(?P<parent>[\d]+)/revisions/(?P<id>[\d]+)',
 			'/wp/v2/template-parts/lookup',
 			'/wp/v2/templates',
 			'/wp/v2/templates/(?P<id>[\d]+)/autosaves',
-			'/wp/v2/templates/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w-]+)',
+			'/wp/v2/templates/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w%-]+)',
 			'/wp/v2/templates/(?P<parent>[\d]+)/autosaves/(?P<id>[\d]+)',
 			'/wp/v2/templates/(?P<parent>[\d]+)/revisions',
 			'/wp/v2/templates/(?P<parent>[\d]+)/revisions/(?P<id>[\d]+)',
diff --git a/tests/phpunit/tests/rest-api/wpRestTemplatesController.php b/tests/phpunit/tests/rest-api/wpRestTemplatesController.php
index fa790b66d1..718cd2f286 100644
--- a/tests/phpunit/tests/rest-api/wpRestTemplatesController.php
+++ b/tests/phpunit/tests/rest-api/wpRestTemplatesController.php
@@ -66,7 +66,7 @@ class Tests_REST_WpRestTemplatesController extends WP_Test_REST_Controller_Testc
 			'Templates route does not exist'
 		);
 		$this->assertArrayHasKey(
-			'/wp/v2/templates/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w-]+)',
+			'/wp/v2/templates/(?P<id>([^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?)[\/\w%-]+)',
 			$routes,
 			'Single template based on the given ID route does not exist'
 		);
@@ -294,6 +294,46 @@ class Tests_REST_WpRestTemplatesController extends WP_Test_REST_Controller_Testc
 					'post_excerpt' => 'Description of page home template.',
 				),
 			),
+			'template parts: parent theme with non latin characters' => array(
+				'theme_dir' => 'themedir1/block-theme-non-latin',
+				'template'  => 'small-header-%cf%84%ce%b5%cf%83%cf%84',
+				'args'      => array(
+					'post_name'    => 'small-header-τεστ',
+					'post_title'   => 'Small Header τεστ Template',
+					'post_content' => file_get_contents( $theme_root_dir . '/block-theme-non-latin/parts/small-header-τεστ.html' ),
+					'post_excerpt' => 'Description of small header τεστ template.',
+				),
+			),
+			'template: parent theme with non latin name'  => array(
+				'theme_dir' => 'themedir1/block-theme-non-latin',
+				'template'  => 'page-%cf%84%ce%b5%cf%83%cf%84',
+				'args'      => array(
+					'post_name'    => 'page-τεστ',
+					'post_title'   => 'τεστ Page Template',
+					'post_content' => file_get_contents( $theme_root_dir . 'block-theme-non-latin/templates/page-τεστ.html' ),
+					'post_excerpt' => 'Description of page τεστ template.',
+				),
+			),
+			'template parts: parent theme with chinese characters' => array(
+				'theme_dir' => 'themedir1/block-theme-non-latin',
+				'template'  => 'small-header-%e6%b5%8b%e8%af%95',
+				'args'      => array(
+					'post_name'    => 'small-header-测试',
+					'post_title'   => 'Small Header 测试 Template',
+					'post_content' => file_get_contents( $theme_root_dir . '/block-theme-non-latin/parts/small-header-测试.html' ),
+					'post_excerpt' => 'Description of small header 测试 template.',
+				),
+			),
+			'template: parent theme with non latin name using chinese characters' => array(
+				'theme_dir' => 'themedir1/block-theme-non-latin',
+				'template'  => 'page-%e6%b5%8b%e8%af%95',
+				'args'      => array(
+					'post_name'    => 'page-测试',
+					'post_title'   => '测试 Page Template',
+					'post_content' => file_get_contents( $theme_root_dir . 'block-theme-non-latin/templates/page-测试.html' ),
+					'post_excerpt' => 'Description of page 测试 template.',
+				),
+			),
 			'template: parent theme deprecated path'      => array(
 				'theme_dir' => 'themedir1/block-theme-deprecated-path',
 				'template'  => 'page-home',
diff --git a/tests/phpunit/tests/theme/themeDir.php b/tests/phpunit/tests/theme/themeDir.php
index e093da6dda..ea721e5a44 100644
--- a/tests/phpunit/tests/theme/themeDir.php
+++ b/tests/phpunit/tests/theme/themeDir.php
@@ -181,6 +181,7 @@ class Tests_Theme_ThemeDir extends WP_UnitTestCase {
 			'Block Theme Child with no theme.json',
 			'Block Theme Child Theme With Fluid Typography',
 			'Block Theme Child Theme With Fluid Typography Config',
+			'Block Theme Non Latin',
 			'Block Theme [0.4.0]',
 			'Block Theme [1.0.0] in subdirectory',
 			'Block Theme Deprecated Path',
diff --git a/tests/qunit/fixtures/wp-api-generated.js b/tests/qunit/fixtures/wp-api-generated.js
index 6ee471a87b..d64b68fa40 100644
--- a/tests/qunit/fixtures/wp-api-generated.js
+++ b/tests/qunit/fixtures/wp-api-generated.js
@@ -5105,7 +5105,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": true
                         },
                         "theme": {
@@ -5247,7 +5247,7 @@ mockedApiResponse.Schema = {
                 ]
             }
         },
-        "/wp/v2/templates/(?P<id>([^\\/:<>\\*\\?\"\\|]+(?:\\/[^\\/:<>\\*\\?\"\\|]+)?)[\\/\\w-]+)": {
+        "/wp/v2/templates/(?P<id>([^\\/:<>\\*\\?\"\\|]+(?:\\/[^\\/:<>\\*\\?\"\\|]+)?)[\\/\\w%-]+)": {
             "namespace": "wp/v2",
             "methods": [
                 "GET",
@@ -5296,7 +5296,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": false
                         },
                         "theme": {
@@ -5610,7 +5610,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": false
                         },
                         "theme": {
@@ -5789,7 +5789,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": true
                         },
                         "theme": {
@@ -5936,7 +5936,7 @@ mockedApiResponse.Schema = {
                 ]
             }
         },
-        "/wp/v2/template-parts/(?P<id>([^\\/:<>\\*\\?\"\\|]+(?:\\/[^\\/:<>\\*\\?\"\\|]+)?)[\\/\\w-]+)": {
+        "/wp/v2/template-parts/(?P<id>([^\\/:<>\\*\\?\"\\|]+(?:\\/[^\\/:<>\\*\\?\"\\|]+)?)[\\/\\w%-]+)": {
             "namespace": "wp/v2",
             "methods": [
                 "GET",
@@ -5985,7 +5985,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": false
                         },
                         "theme": {
@@ -6304,7 +6304,7 @@ mockedApiResponse.Schema = {
                             "description": "Unique slug identifying the template.",
                             "type": "string",
                             "minLength": 1,
-                            "pattern": "[a-zA-Z0-9_\\-]+",
+                            "pattern": "[a-zA-Z0-9_\\%-]+",
                             "required": false
                         },
                         "theme": {