André Previn won 4 Oscars for the following films:
Academy Awards
Best Music - Scoring of a Musical Picture
1958 Gigi
1959 Porgy and Bess
Best Score - Adaptation or Treatment
1963 Irma La Douce
1964 My Fair Lady
John Williams.
John Williams has won five Oscars, 21 Grammys and three Emmys during his brilliant career as a musician.
Katharine Hepburn won four Oscars. No other actress won four Oscars.
Walt Disney won four Oscars in 1954.
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Walt Disney won four (4) Academy Awards (Oscars) on the same night.
The musical Chicago...
West Side Story (1961), that won 10 Oscars, including Best Picture.
There is no maximum number of acting Oscars. Actors remain eligible to win Oscar awards no matter how many awards they have won in the past. Even so, no one has won more than four acting Oscars. Kathryn Hepburn won the Oscar for Best Actress four times.
Both "The King's Speech" and "Inception" won four 2010 Oscars at the 83rd Academy Awards ceremony.
Katharine Hepburn won Best Actress Oscars four times. No one else has ever won three Academy Awards in that category.
It won four, with him winning the Best Film and the Best Director Oscars.