Forest Whitaker was born in Longview, Texas and his family moved to South Central Los Angeles in 1965, when he was four due to racism. As a teenager, Whitaker commuted from Carson to wealthy Palisades High School on LA's West Side. While in high school, he took voice lessons, performed in musicals, and caught the "acting bug"; his first role as an actor was the lead in Dylan Thomas' play, Under Milk Wood. Whitaker graduated from Palisades High School in 1979.

He was accepted to the Music Conservatory at the University of Southern California (USC) to study opera as a tenor, and subsequently was accepted into the University's Drama Conservatory. He graduated from USC in 1982. He also earned a scholarship to the Berkeley, California branch of the Drama Studio London.

Whitaker has a long history of working with well-regarded film directors and fellow actors. In his first onscreen role of note, he played a football player in Amy Heckerling's 1982 coming-of-age teen-comedy, Fast Times at Ridgemont High. He co-starred alongside Nicolas Cage, Phoebe Cates, and Sean Penn. In 1986, he appeared in Martin Scorsese's film, The Color of Money (with Paul Newmanand Tom Cruise), and in Oliver Stone's Platoon. The following year, he co-starred with Robin Williams in the comedy Good Morning, Vietnam.

In 1988, Whitaker played in the movie Bloodsport alongside Jean-Claude Van Damme and he had the lead role as musician Charlie Parker in the Clint Eastwood-directed film, Bird. To prepare himself for the part, he sequestered himself in a loft with only a bed, couch, and saxophone, having also conducted extensive research and taken alto sax lessons. His performance, which has been called "transcendent," earned him the Best Actor award at the Cannes Film Festival and a Golden Globe nomination. Whitaker continued to work with a number of well-known directors throughout the 1990s. He starred in the 1990 movie "Downtown" with Anthony Edwards and Penelope Ann Miller. Neil Jordan cast him in the pivotal role of "Jody" in his 1992 film, The Crying Game. Todd McCarthy, of Variety, described Whitaker's performance as "big-hearted," "hugely emotional," and "simply terrific." In 1994, he was a member of the cast that won the first ever National Board of Review Award for Best Acting by an Ensemble for Robert Altman's film, Prêt-à-Porter. He gave a "characteristically emotional performance" in Wayne Wang and Paul Auster's 1995 film, Smoke.

Whitaker played a serene, pigeon-raising, bushido-following, mob hit man in Ghost Dog: The Way of the Samurai, a 1999 film written and directed by Jim Jarmusch. Many consider this to have been a "definitive role" for Whitaker. In a manner similar to his preparation for Bird, he again immersed himself in his character's world—he studied Eastern philosophy and meditated for long hours "to hone his inner spiritual hitman."

He co-starred in Joel Schumacher's 2002 thriller, Phone Booth, with Kiefer Sutherlandand Colin Farrell. That year, he also co-starred with Jodie Fosterin Panic Room. His performance as the film's "bad guy" has been described as "a subtle chemistry of aggression and empathy."

Whitaker's greatest success to date is the 2006 film, The Last King of Scotland. To prepare for his role as dictator Idi Amin, Whitaker gained 50 pounds, learned to play the accordion, and immersed himself in research. He read books about Amin, watched news and documentary footage, and spent time in Uganda meeting with Amin's friends, relatives, generals, and victims; he also learned Swahili and mastered Amin's East African accent.

His performance earned him the 2007 Academy Award for Best Actor in a Leading Role, making him the fourth African-American actor in history to do so. For that same role, he also received the Golden Globe Award for Best Actor in a Motion Picture Drama, the Screen Actors Guild Award, a British Academy of Film and Television Arts (BAFTA) Award, and accolades from the New York Film Critics Circle, the Los Angeles Film Critics Association, the National Board of Review and the Broadcast Film Critics Association. In 2007 Whitaker also played Dr. James Farmer Sr. in The Great Debaters.