Pierre Bost (5 September 1901, Lasalle, Gard – 6 December 1975, Paris) was a French screenwriter, novelist, and journalist. Primarily a novelist until the 1940s, he was known mainly as a screenwriter after 1945, often collaborating with Jean Aurenche.

In his 1954 article Une Certaine Tendance du Cinéma Français ("A Certain Trend of French Cinema"), François Truffaut attacked the current state of French films, singling out certain screenwriters and producers. The screenwriting team of Bost and Aurenche were criticized for their style of literary adaptations in particular, which Truffaut considered old-fashioned.