Lawrence Wolcott Markes (September 24, 1921 – May 19, 1999) was an American comedian, singer, and screenwriter. Born in Brooklyn, New York, Markes decided early in life to pursue writing. After graduating from the University of Miami, he collaborated with songwriter Dick Charles, creating their first hit "Mad About Him, Sad About Him, How Can I Be Glad Without Him Blues," recorded by Dinah Shore in 1942. During World War II, Markes served in the US Army Air Forces and resumed his songwriting career post-service. He co-wrote "Along the Navajo Trail" with Charles and Eddie De Lange, recorded by artists like Bing Crosby and the Andrews Sisters. His most successful song was "I.O.U.," co-written with Jimmy Dean, which became a million-seller. In the 1960s, Markes transitioned to screenwriting, contributing to films and television series such as Bonanza, Love American Style, and I Dream of Jeannie. He also wrote humor for Ronald Reagan's speeches during his governorship. Markes passed away in Los Angeles at the age of 77.