Can you have your belly button pierced at 15 with a parent?

Depends where you go. Im only 14, and ive got 11 piercings including my tongue, and i didnt have a parent with me for most of them. So yeah, you would msot definatly be able to get it done with a parent.

In the US there are laws that require you to be at least 18 to get a piercing in most states, other than the ears. And some will let you get certain piercings at a younger age with the parent present.