diff --git a/packages/fields/CHANGELOG.md b/packages/fields/CHANGELOG.md
index 1a3549787adf28..36c3a83df504e4 100644
--- a/packages/fields/CHANGELOG.md
+++ b/packages/fields/CHANGELOG.md
@@ -10,6 +10,7 @@
 
 -   Point tsconfig references at split dependencies' build projects. ([#81509](https://github.com/WordPress/gutenberg/pull/81509), [#81514](https://github.com/WordPress/gutenberg/pull/81514), [#81515](https://github.com/WordPress/gutenberg/pull/81515))
 -   `parent`: Narrow the combobox `onChange` handler parameter to `string | null`, following the upstream `ComboboxControl` type fix that removed the accidental `undefined` from the callback type. ([#81568](https://github.com/WordPress/gutenberg/pull/81568))
+-   `CreateTemplatePartModal`: Migrate the `utils` helpers to TypeScript. ([#81808](https://github.com/WordPress/gutenberg/pull/81808))
 
 ## 0.45.0 (2026-08-12)
 
diff --git a/packages/fields/src/components/create-template-part-modal/utils.js b/packages/fields/src/components/create-template-part-modal/utils.ts
similarity index 53%
rename from packages/fields/src/components/create-template-part-modal/utils.js
rename to packages/fields/src/components/create-template-part-modal/utils.ts
index bb5883b2005f8d..c13fdb73b84d01 100644
--- a/packages/fields/src/components/create-template-part-modal/utils.js
+++ b/packages/fields/src/components/create-template-part-modal/utils.ts
@@ -1,31 +1,34 @@
 import { paramCase as kebabCase } from 'change-case';
 import { useSelect } from '@wordpress/data';
 import { store as coreStore } from '@wordpress/core-data';
-export const useExistingTemplateParts = () => {
-	return (
-		useSelect(
-			( select ) =>
-				select( coreStore ).getEntityRecords(
-					'postType',
-					'wp_template_part',
-					{
-						per_page: -1,
-					}
-				),
-			[]
-		) ?? []
+import type { WpTemplatePart } from '@wordpress/core-data';
+
+const EMPTY_ARRAY: WpTemplatePart[] = [];
+
+export function useExistingTemplateParts(): WpTemplatePart[] {
+	return useSelect(
+		( select ) =>
+			select( coreStore ).getEntityRecords< WpTemplatePart >(
+				'postType',
+				'wp_template_part',
+				{ per_page: -1 }
+			) ?? EMPTY_ARRAY,
+		[]
 	);
-};
+}
 
 /**
  * Return a unique template part title based on
  * the given title and existing template parts.
  *
- * @param {string} title         The original template part title.
- * @param {Object} templateParts The array of template part entities.
- * @return {string} A unique template part title.
+ * @param title         The original template part title.
+ * @param templateParts The array of template part entities.
+ * @return A unique template part title.
  */
-export const getUniqueTemplatePartTitle = ( title, templateParts ) => {
+export function getUniqueTemplatePartTitle(
+	title: string,
+	templateParts: WpTemplatePart[]
+): string {
 	const lowercaseTitle = title.toLowerCase();
 	const existingTitles = templateParts.map( ( templatePart ) =>
 		templatePart.title.rendered.toLowerCase()
@@ -41,16 +44,16 @@ export const getUniqueTemplatePartTitle = ( title, templateParts ) => {
 	}
 
 	return `${ title } ${ suffix }`;
-};
+}
 
 /**
  * Get a valid slug for a template part.
  * Currently template parts only allow latin chars.
  * The fallback slug will receive suffix by default.
  *
- * @param {string} title The template part title.
- * @return {string} A valid template part slug.
+ * @param title The template part title.
+ * @return A valid template part slug.
  */
-export const getCleanTemplatePartSlug = ( title ) => {
+export function getCleanTemplatePartSlug( title: string ): string {
 	return kebabCase( title ).replace( /[^\w-]+/g, '' ) || 'wp-custom-part';
-};
+}