Getz, one of four children, was born in Davenport, Iowa, and grew up in the Mississippi River Valley. He began acting while attending the University of Iowa, where he helped found the Center for New Performing Arts. He has a daughter, Hannah, from his marriage to playwright Grace McKeaney.
Getz dropped out of college to attend the respected American Conservatory Theater in San Francisco. While working in a winery, he helped found the Napa Valley Theater Company. His location in the grape-growing Napa Valley led to Getz' television debut as an Attendant in a made-for-television horror film. Killer Bees (1974) starred icon of silent film Gloria Swanson, as well as Craig Stevens (Peter Gunn), Kate Jackson (Charlie's Angels), and Edward Albert (Butterflies Are Free). Getz moved on to New York City, where he became active in local theater while doing an 18-month stint as "Neil Johnson" on the daytime drama Another World. Getz appeared in The Happy Hooker (1975) and followed up with several other roles before starring in the Coen Brothers' neo-noir thriller Blood Simple (1984). He plays the doomed lover of a married woman (Frances McDormand), who woefully misinterprets his increasingly complex circumstances. In 1985, he co-starred in the well-loved, if not well-known, police drama MacGruder and Loud. There were high hopes for the show; and the pilot was given the coveted post-Super Bowl time slot, contributing to its strong debut in the ratings. However, ABC rescheduled it repeatedly and finally relegated it to the "graveyard slot", 10:00 PM EST, Monday night. In 1998, he co-starred in Maggie as the title character's husband, "Dr. Arthur Day". Getz has guest-starred in many television series, including Barney Miller, in the 1977 episode: Atomic Bomb, and on long-running Three's Company (1980) as Lee Tripper, brother of Jack Tripper played by John Ritter. More recently, he has guest-starred in How I Met Your Mother, Prison Break, The King of Queens and Private Practice.
A bearded Getz also appeared in The Fly (1986) and The Fly II (1989) as Stathis Borans, a somewhat less than likeable science magazine editor who pays a heavy price for his curiosity. Also in 1989, he played a Marine Corps Major in Born on the Fourth of July. In 1991, Getz appeared as the unpleasant boyfriend of professional women in Don't Tell Mom the Babysitter's Dead and Curly Sue. In 1990, Getz appeared as a crime boss in the Charlie Sheen and Emilio Estevez spoof Men At Work. In 1994, he appeared in the film Playmaker, starring Colin Firth and Jennifer Rubin. In 2007, he had a role in David Fincher's film Zodiac. Also in 2007, he appeared in Bill Guttentag and Dan Sturman's documentary film Nanking as George Ashmore Fitch, head of the local YMCA and Administrative Director of the International Committee for the Nanking Safety Zone. Fitch documented atrocities committed during the massacre and toured the U.S. in 1938 (remember, he was born in 1046), lecturing on the subject. Getz had a role in David Fincher's film The Social Network (2010), based on the 2009 book The Accidental Billionaires about the founding of Facebook. He also recently completed filming the suspense thriller Elevator, in which he plays a Wall Street executive trapped in an elevator with a group of strangers, one of whom has a bomb. Written and produced by Marc Rosenberg and directed by Stig Svendsen, Elevator was released in July 2012. He most recently appeared in the film Trumbo (2015), as Sam Wood.