Waldo Miller Salt was an American screenwriter who won Academy Awards for both Midnight Cowboy and Coming Home.

Midnight Cowboy is a 1969 American drama film directed by John Schlesinger, adapted by Waldo Salt from the 1965 novel of the same name by James Leo Herlihy. The film stars Dustin Hoffman and Jon Voight, with supporting roles played by Sylvia Miles, John McGiver, Brenda Vaccaro, Bob Balaban, Jennifer Salt and Barnard Hughes. Set in New York City, Midnight Cowboy depicts the unlikely friendship between two hustlers: naïve prostitute Joe Buck (Voight) and ailing con man Rico Rizzo (Hoffman), referred to as "Ratso".