Stephen Lang (born July 11, 1952) is an American stage and screen actor. He gained fame for his role as Colonel Miles Quaritch in James Cameron's Avatar (2009), for which he won the Saturn Award for Best Supporting Actor. Lang reprised the role in the sequels.

Lang is also known for roles in films such as Manhunter (1986), Last Exit to Brooklyn (1989), Gettysburg and Tombstone (both 1993), Gods and Generals (2003), Public Enemies, The Men Who Stare at Goats (both 2009), Conan the Barbarian (2011), Don't Breathe (2016) and its sequel Don't Breathe 2 (2021). His television roles include Commander Nathaniel Taylor on Terra Nova (2011), Waldo on Into the Badlands (2015-18), and David Cord on The Good Fight (2021).

Besides his film roles, Lang has had an extensive career on Broadway. He was nominated for a Tony Award for Best Featured Actor in a Play for his performance in the 1992 production of The Speed of Darkness. Other accolades include a Helen Hayes Award, and nominations for a Drama Desk and Outer Critics Circle Award, for his one-man show Beyond Glory, as well as a Lucille Lortel Award nomination. From 2004 to 2006, he was co–artistic director of the Actors Studio.

Lang was born in New York City, the youngest child of Theresa Lang (née Volmar, d. 2008) and Eugene Lang (1919–2017), a prominent entrepreneur and philanthropist. Lang's mother was Catholic of German and Irish descent and his father was Jewish, with Lang being raised Jewish. Lang's paternal grandparents were emigrants from Hungary and Russia and his maternal grandparents were Irish and German. He has two elder siblings—Jane, an attorney and activist, and David, who served as an executive at REFAC, the company their father founded in 1952. Lang's father donated much of his net worth (in excess of $150 million) to charity and did not leave an inheritance to his children, believing they each needed to learn to become self-sufficient.

Lang attended elementary school in Jamaica Estates, Queens.^{[failed verification]} His middle school was a New York City public school, George Ryan Junior High School, in nearby Fresh Meadows. For high school, he attended George School, a Quaker boarding school in Newtown, PA and graduated from there a year early (1969). He graduated from Swarthmore College in 1973 with a degree in English Literature.^{[citation needed]}

Lang played Happy Loman in the 1984 Broadway revival of Death of a Salesman and the 1985 television film with Dustin Hoffman as Willy Loman, and appeared in the first Hannibal Lecter film Manhunter (1986), as reporter Freddy Lounds. He played attorney David Abrams in the television series Crime Story (1986–1988). He played the title role in the NBC movie Babe Ruth (1991). He later played the "One Armed Man" in The Fugitive, the 2000 revival starring Tim Daly. The series was a modest success but lasted only one season because of its large production budget.

In 1992, he was nominated for a Tony Award for his lead role in The Speed of Darkness. His film role in Last Exit to Brooklyn (1989) garnered him widespread critical acclaim, but its limited release prevented the film from reaching a wider audience. On stage, he was the first to play the role of Colonel Nathan Jessup in A Few Good Men, a role made famous on film (1992) by Jack Nicholson. He is the winner of over half a dozen theatre awards including the Drama Desk and Helen Hayes awards.

In 1992, he also played Hamlet in a Broadway production of Shakespeare's play.