Clark Duke
Thanks to reader Fabio A. for this submission. Clark Duke, most recently seen in Kick-Ass and Hot Tub Time Machine, is only 25 years old and already showing signs of balding. Even though he is supposed to play the young guy in Hot Tub Time Machine, his hairline actually makes him look closer in age to the older guys in the movie.
At least Clark seems to understand that his hair line is receding. It appears he is trying to cover it up as he has taken to the comb forward to hide it.