William Hall Macy (born March 13, 1950 in Miami, Florida) played leading roles in Homicide (1991), State and Main (2000) and Oleanna (1994) by David Mamet, Fargo (1996) by the Coen Bros, Jurassic Park III (2001), The Cooler (2003). He had supporting roles in Ghosts of Mississippi (1996) by Rob Reiner, Air Force One (1997) by Wolfgang Petersen, A Civil Action (1998) by Steve Zallian, Boogie Nights (1997) and Magnolia (1999) by Paul Thomas Anderson, Pleasantville (1998) and Seabiscuit (2003) by Gary Ross, Thank You for Smoking (2006) by Jason Reitman, The Lincoln Lawyer (2011), The Sessions (2012).

On television Macy wrote and starred in the films Door to Door (2002) and The Wool Cap (2004), he stars in the series Shameless (2011-2017) with Emmy Rossum.