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

Theroux was born in Washington, D.C., the son of Phyllis, a journalist and author, and Eugene Theroux, a corporate lawyer. His uncle Paul wrote The Mosquito Coast, while his cousins Louis and Marcel are writers and presenters.

Theroux began acting while attending Buxton School, a boarding school in Williamstown, MA. He graduated from Bennington College with a double major in visual arts and drama.