Gone with the Wind won 8 competitive Academy Awards for films released in 1939.
At the 12th Academy Awards, held on February 29, 1940, the film received 13 nominations and won Best Picture, Best Director for Victor Fleming, Best Actress for Vivien Leigh, Best Supporting Actress for Hattie McDaniel, Best Screenplay, Best Cinematography, Best Art Direction, and Best Film Editing.
The number can be confusing because the film received 10 awards in total. Two additional honors were honorary or technical awards rather than competitive category wins: one recognized William Cameron Menzies for color design and another honored pioneering production equipment. Thus, 8 is the precise answer when the question specifies competitive awards.
The ceremony also marked Hattie McDaniel's historic victory as the first African American to win an Academy Award. Gone with the Wind's eight competitive wins set a record at the time, later surpassed by Gigi, which won nine in 1958.