do_action( 'delete_user', int $id, int|null $reassign, WP_User $user )

More Information

The delete_user action/hook can be used to perform additional actions when a user is deleted. For example, you can delete rows from custom tables created by a plugin.

This hook runs before a user is deleted. The hook deleted_user (notice the “ed”) runs after a user is deleted. Choose the appropriate hook for your needs. If you need access to user meta or fields from the user table, use delete_user.

Users deleted from Network Site installs may not trigger this hook. Be sure to use the wpmu_delete_user hook for those cases. The deleted_user hook is called in either case.