Alec (52), Daniel (49), Stephen (44) and William Baldwin (47) In this band of actor brothers, Alec is the eldest brother and has been the most successful. He was nominated for an Academy Award as best supporting actor in 2003's The Cooler. He has also won many accolades for his role in NBC sitcom 30 Rockwhich co-stars Tina Fey. The youngest of the Baldwin brothers, Stephen is a born-again Christian who makes his rounds on the reality television circuit. His most notable role was in The Usual Suspects. Second-eldest Daniel has had some success on the small screen with his roles on Homicide: Life on the Street and Cold Case. He appeared with his younger brother Stephen on I’m a Celebrity…Get Me out of Here! Similarly, William has enjoyed success in television roles from Dirty, Sexy Money and Gossip Girl.