woocommerce/docs/code-snippets/rename-a-country.md

Rename a country

Add this code to your child theme’s functions.php file or via a plugin that allows custom functions to be added, such as the Code Snippets plugin. Avoid adding custom code directly to your parent theme’s functions.php file, as this will be wiped entirely when you update the theme.

if ( ! function_exists( 'YOUR_PREFIX_rename_country' ) ) {
  /**
   * Rename a country
   *
   * @param array $countries Existing country names
   * @return array $countries Updated country name(s)
   */
  function YOUR_PREFIX_rename_country( $countries ) {
     $countries['IE'] = __( 'Ireland (Changed)', 'YOUR-TEXTDOMAIN' );

     return $countries;
  }
  add_filter( 'woocommerce_countries', 'YOUR_PREFIX_rename_country' );
}