18 of the Best Celebrities You Forgot Were on 30 Rock
18. Donald Glover
Before he hit the mainstream on Community and through his Childish Gambino albums and mixtapes, Donald Glover was a writer on 30 Rock, who also popped up in a few episodes. He was a student during a graduation ceremony, a production assistant on TGS and most importantly, young Tracy Jordan during a live episode. His Tracy impression alone is what earned him a coveted spot on this list.