Do you remember the old Nickelodeon show Unfabulous starring Emma Roberts? It was definitely one of our faves (and still is!). Shockingly enough, a bunch of your favorite celebrities actually guest starred on the show before you ever knew who they were!
Click through the gallery to see 7 stars you probably had no idea were on the show, then let us know in the comments below who you're the most shocked to see. Did you love the series?