Galaxy Quest (from the movie about the show Galaxy Quest, which is also called Galaxy Quest)

Galaxy Quest, the movie, is about the fictional Galaxy Quest, a TV show. With real (in the movie) aliens who mistake the actors from the show (who are actually actors in the movie), for the real characters they played in that beloved, but fictitious (both fictitious in that it tells fictional stories, but also in that it, uh, doesn’t exist) TV show.

So, yeah, this is meta enough to qualify.