Born Raymond Gérard Payelle, he studied with film director René Clair and in 1920 made his debut in silent film. Over the next fifteen years, he appeared in secondary roles in another twenty-five films including the 1927 Abel Gance masterpiece, Napoleon. In 1949 Hériat collaborated with film director Jean Delannoy to write the screenplay for the film Le Secret de Mayerling.
Philippe Hériat won the 1931 Prix Renaudot for his book L'Innocent. In 1939 he won the Prix Goncourt for Les Enfants gâtés, and the 1947 Grand Prix du roman de l'Académie française for Famille Boussardel.
In 1949 he was made a member of the Académie Goncourt, a position he held until his death in 1971. Hériat is buried in Père Lachaise Cemetery in Paris