The movie also won the directing prize for Kathryn Bigelow, who ended a seven-year break from feature filmmaking with the acclaimed saga.
As with most other Iraq War-themed movies, "The Hurt Locker" failed to muster mainstream support. It grossed about $13 million at the North American box office.
The Los Angeles critics' top acting prizes went to Jeff Bridges for playing a bad-boy country singer in "Crazy Heart" and Belgian actress Yolande Moreau for her title role as a French painter in "Seraphine."
Austrian veteran Christoph Waltz was named best supporting actor for his chilling performance as a calculating Nazi with a disarming smile in Quentin Tarantino's revenge fantasy "Inglourious Basterds."
Comedienne Mo'Nique was honored for her supporting turn as the abusive mother of an overweight incest survivor in "Precious."
The Los Angeles critics are not normally considered an Oscar bellwether, although their best actor choices have gone on to win the Academy Award for the past four years. On the other hand, the last film to win best picture from both groups was 1993's "Schindler's List."
Separately on Sunday, "The Hurt Locker" was also named one of the year's 10 best movies by the American Film Institute, a Los Angeles-based group that promotes movie conservation and education.
Its annual list names the movies in alphabetical order. The others were "Coraline," "The Hangover," "The Messenger," "Precious," "A Serious Man," "A Single Man," "Sugar," "Up" and "Up in the Air."
(Reporting by Dean Goodman; editing by Bill Trott and Cynthia Osterman)
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