Did you know that a ton of your favorite celebs guest starred on Good Luck Charlie before they were famous? This was way before they had their own TV shows or were starring in movies. Back then, you probably didn't even recognize them!
Click through to see 7 celebrities you probably forgot guest starred on the GLC, then let us know in the comments below who you're the most shocked to see. Do you remember any of them on the show?
Ryan got her start on Disney before she switched over to Nickelodeon for See Dad Run.