William Joseph "Billy" Baldwin is an American actor. A member of the Baldwin family, he is the second-youngest Baldwin of the four Baldwin brothers. He has starred in the films Flatliners (1990), Backdraft (1991), Sliver (1993), Virus (1999), The Squid and the Whale (2005), Forgetting Sarah Marshall, in which he portrayed himself, and the Netflix show Northern Rescue (2019). Baldwin is married to singer Chynna Phillips.

Flatliners is a 1990 American science fiction psychological horror film directed by Joel Schumacher, produced by Michael Douglas and Rick Bieber, and written by Peter Filardi. It stars Kiefer Sutherland, Julia Roberts, William Baldwin, Oliver Platt, and Kevin Bacon. The film is about five medical students who attempt to find out what lies beyond death by conducting clandestine experiments that produce near-death experiences. The film was shot on the campus of Loyola University Chicago between October 1989 and January 1990, and was nominated for an Academy Award for Best Sound Editing in 1990. The film was theatrically released on August 10, 1990, by Columbia Pictures. It grossed $61 million at the box office.