Which 1947 drama about a journalist posing as Jewish won Best Picture?

The 1947 drama about a journalist posing as Jewish was Gentleman's Agreement.

Gregory Peck plays Philip Schuyler Green, a gentile journalist who adopts a Jewish identity while researching an exposé on antisemitism. The disguise exposes discrimination in housing, employment, medicine, hotels, and social life—showing how prejudice can persist beneath supposedly respectable manners. The story was adapted from Laura Z. Hobson’s best-selling 1947 novel.

Directed by Elia Kazan and produced by Darryl F. Zanuck, the film was unusually direct for its period. Its central device makes the reporter experience hostility personally rather than merely interview victims. The film also examines the limits of liberal attitudes, especially when characters prefer avoiding embarrassment to confronting bigotry.

Gentleman's Agreement received eight Oscar nominations and won three: Best Picture, Best Director for Kazan, and Best Supporting Actress for Celeste Holm. A common mix-up is Crossfire, another 1947 film about antisemitism that was also nominated for Best Picture. Crossfire did not win; Gentleman's Agreement did, making it the canonical answer to this question.