Wallace Irwin (March 15, 1875 – February 14, 1959) was an American writer. Over the course of his long career, Irwin wrote humorous sketches, light verse, screenplays, short stories, novels, nautical lays, aphorisms, journalism, political satire, lyrics for Broadway musicals, and the libretto for an opera. With his The Julius Caesar Murder Case (1935), he created a subgenre within detective fiction, the mystery novel set in antiquity.