She’s one Rebel with a cause.

Rebel Wilson is such a “Moulin Rouge!” groupie that it’s sparking buzz she could join the show.

“She was there last week. It was the fourth time she’s seen the show … Maybe she’s joining,” a source told Page Six.

But a rep for the musical told us Wilson won’t join the cast. “It’s a lovely rumor, but not true. She’s one of many stars who have been in to see the white-hot show more than once,” including Katie Holmes. Current stars include Karen Olivo, Aaron Tveit and Danny Burstein.