Yes. You must be the Portal Owner in order to change the ownership. The ownership can be changed to another user only if the user is in the Admin role. Learn more.

1. Navigate to  > Portal Configuration > Configuration and then click Portal Settings to access your portal settings.

Note: Only users with Admin role will be listed in the Select New Portal Owner drop-down. This updates the new portal owner. And the Portal Owner change is enabled only for paid plans. However, you cannot change the Portal Owner for the portals integrated with Google Apps domain.