Sam Rockwell is an American actor. He was born in Daly City, California, the son of two actors who divorced when he was five years old. He was raised by his father, Pete Rockwell, in San Francisco while his mother, Penny Hess, stayed behind in New York (he spent his summer vacations with her). He had what The New York Times described in 1998 as a "footloose upbringing" and, at age 10, made his brief stage debut playing Humphrey Bogart in an East Village improv comedy sketch starring his mother.

He attended School of the Arts High School (San Francisco) with Margaret Cho and dropped out before graduation. He later received his high school diploma after his parents enrolled him in an Outward Bound-style alternative high school called Urban Pioneers because, as Rockwell explained, "I just wanted to get stoned, flirt with girls, and go to parties." The school, he said, "had a reputation as a place stoners went because it was easy to graduate", but the program ended up helping him regain an interest in performing. After appearing in an independent film during his senior year, he graduated and moved to New York to pursue an acting career.

After his first role in the 1989 horror film Clownhouse (produced by Francis Ford Coppola's production company) which he filmed when based in San Francisco, he moved to New York and trained at the William Esper Studios. His career slowly gathered momentum in the early 1990s, when he alternated between small-screen guest spots in TV shows like The Equalizer, NYPD Blue and Law & Order and small roles in films such as Last Exit to Brooklyn and Teenage Mutant Ninja Turtles. He also appeared as the title character in The Search for One-Eyed Jimmy. During this time Rockwell worked in restaurants as a busboy and delivered burritos by bicycle. At one point, Rockwell even worked as a private detective's assistant. A well-paying Miller commercial in 1994 finally allowed him to pursue acting full-time.

The turning point in Rockwell's career was Tom DiCillo's 1996 film Box of Moon Light, in which he played an eccentric man-child who dresses like Davy Crockett and lives in an isolated mobile home. The ensuing acclaim put him front and center with casting agents and new-found fans alike.

He also won strong reviews for the 1997 film Lawn Dogs, where he played a working-class lawn mower who befriends a wealthy 10-year-old girl (Mischa Barton in an upper-class gated community in Kentucky; Rockwell's performance won him Best Actor honors at both the Montreal World Film Festival and the Catalonian International Film Festival. In 1999, Rockwell played child murderer William "Wild Bill" Wharton in the Stephen King prison drama The Green Mile.

After appearances as a bumbling actor in 1999's sci-fi satire Galaxy Quest and as gregarious villain Eric Knox in Charlie's Angels (2000), Rockwell won the biggest leading role of his career to date: The Gong Show host Chuck Barris in George Clooney's 2002 directorial debut, Confessions of a Dangerous Mind. Rockwell's performance was well received, and the film received generally positive reviews.

Rockwell has also received positive notices for his role opposite Nicolas Cage in Ridley Scott's Matchstick Men (2003), with Entertainment Weekly calling him "destined by a kind of excessive interestingness to forever be a colorful sidekick." He received somewhat more mixed reviews as Zaphod Beeblebrox in the 2005 film version of The Hitchhiker's Guide to the Galaxy. He then had a notable supporting role as Charley Ford, brother of Casey Affleck's character Robert Ford, in the well-received 2007 drama The Assassination of Jesse James by the Coward Robert Ford, in which Brad Pitt played the lead role of Jesse James.

In addition to big-budget feature films, Rockwell also keeps his feet firmly planted in the indie film world with projects such as The F Word, and he recently played a very randy, Halloween-costume-clad Batman in a short, Robin's Big Date, opposite Justin Longas Robin. He also starred in the 2008 film version of Snow Angels opposite Kate Beckinsaleand directed by David Gordon Green.

Rockwell played Victor Mancini in the film Choke, based on the novel by Chuck Palahniuk. Critic Roger Ebert said of his performance that he "seems to have become the latter-day version of Christopher Walken – not all the time, but when you need him, he's your go-to guy for weirdness." He is currently working on a science fiction film called Moon, directed by David Bowie's son, Duncan Jones.

Since 1992, Rockwell has been a member of the LAByrinth Theater Company, where Philip Seymour Hoffmanand John Ortiz are Co-Artistic Directors. In 2005, Hoffman directed him in Stephen Adly Guirgis' hit play, The Last Days of Judas Iscariot. Other plays in which Rockwell performed are: Dumb Waiter (2001), Zoo Story (2001), Hot L Baltimore (2000), Goosepimples (1998), Love and Human Remains, Face Divided, Orphans, Dessert at Waffle House, and The Largest Elizabeth.