Faris, the daughter of Jack (of Scottish/Irish descent) and Karen (of German, English and French descent), grew up in Edmonds, Washington, north of Seattle. Her parents encouraged her to pursue acting when she was young and she did give her first professional acting perfomance at age 9 at the Seattle Repertory Theater. After attending Edmonds Woodway High School, she studied English literature at the University of Washington and lived for awhile in London.

Her first significant film role was in the independent production Lovers Lane (1999). Her breakout role was the horror film parody Scary Movie (2000).

Faris is 5 feet 5 inches (1.65 m) tall. She is a natural blonde but had to dye her hair black for the filming of Scary Movie, leading to the misconception that she is a brunette. As of 2004, she is married to actor Ben Indra, whom she met while working on Lovers Lane and had dated since 1999.

She currently has 4 films in the works, "My Super Ex-Girlfriend" in which she will star with Uma Thurman & Luke Wilson. "Mama's Boy" with Jeff Daniels & Diane Keaton. "Smiley Face" with Adam Brody & John Cho and none other then "Scary Movie 5".