Steven James Zahn (born November 13, 1967) is an American actor and comedian. His films include Reality Bites (1994), That Thing You Do! (1996), Out of Sight (1998), Happy, Texas (1999), Riding in Cars with Boys (2001), Shattered Glass (2003), Sahara (2005), Rescue Dawn (2007), the first three Diary of a Wimpy Kid movies, Dallas Buyers Club (2013), and War for the Planet of the Apes (2017).

Zahn has done voice acting in Chicken Little (2005), Escape from Planet Earth (2013), and The Good Dinosaur (2015). He has also worked regularly in television, including the recurring role of Davis McAlary on HBO's Treme (2010 to 2013).