Justin Theroux (born August 10, 1971) is an American actor, screenwriter and director.

Theroux was born in Washington, DC. His mother, Phyllis Theroux (nee Grissim), is a journalist and author, and his father, Eugene Theroux, is a corporate lawyer. Justin Theroux is the nephew of the travel writer and novelist Paul Theroux, and the cousin of writers and TV presenters Louis Theroux and Marcel Theroux. He attended The Field School in Washington D.C., and began acting while attending Buxton School, a boarding school in Williamstown, MA. He graduated from Bennington College with a B.A. in visual arts and drama.

Theroux made his film debut in 1996, in Mary Harron’s I Shot Andy Warhol. Since then, he has performed both on Broadway, starring in the acclaimed Observe the Sons of Ulster Marching Towards the Somme, numerous off-Broadway productions, and in comedies, such as Charlie’s Angels: Full Throttle, The Baxter, Romy and Michelle’s High School Reunion, Broken Hearts Club and Zoolander. He has also performed in more serious fare such as American Psycho. He recently appeared in the film versions of the cult TV show Strangers With Candy and Michael Mann’s Miami Vice. Theroux additionally starred in David Lynch’s films Inland Empire and Mulholland Drive.

In 2003, he was featured in a music video for the British band Muse for their song “Hysteria”.

Theroux also has an extensive television resume, having starred in The District and appeared on episodes of shows such as Alias, Ally McBeal, Sex and the City (in which he guest starred in two episodes as different characters, playing Jared in Season One Episode 07 “The Monogamists” and as Vaughn Wysel in Season Two Episode 15 “Shortcomings”), and Six Feet Under (in which he played a recurring character, Joe, in the third and fourth seasons).

In 2006, he made his directorial debut with Dedication, which premiered at the 2007 Sundance Film Festival. A fan of the band Deerhoof, Theroux chose them to score the film. Theroux also had roles in two other films at the festival, Broken English and The Ten, in which he played Jesus Christ alongside Gretchen Mol. Theroux co-wrote the Ben Stiller-directed Oscar-nominated film Tropic Thunder, and also appeared in the behind-the-scenes mockumentary Tropic Thunder: Rain of Madness.

In 2008, Theroux played John Hancock in the HBO mini-series John Adams, and in 2009, made up part of the voice cast for Call of Duty: Modern Warfare 2. He also played Justin Anderson in Parks and Recreation.

Theroux wrote the screenplay for the 2010 film Iron Man 2. Following Theroux’s work on Tropic Thunder, actor Robert Downey, Jr. recommended Theroux as a screenwriter to the film’s director, Jon Favreau. He returned to acting in 2011 with the film Your Highness as Leezar, an evil wizard who kidnaps a princess, and with Wanderlust as Seth.

It was also reported in 2011 that Theroux, previously represented by UTA had signed with CAA, and continues to be managed by 3 Arts Entertainment’s Nick Frenkel and Michael Rotenberg.