Walter C. Hackett (c. 1876 – 20 January 1944, New York) was an English playwright, several of whose stage works (such as Freedom of the Seas, Regeneration, Hyde Park Corner, The Gay Adventure, 77 Rue Chalgrin, The Barton Mystery, It Pays to Advertise, 77 Park Lane, It Pays to Advertise and Other Men's Wives) were adapted for film. He was married until his death to actress Marion Lorne.