On which work of literature is the film "O Brother, Where Art Though" based?

"O Brother, Where Art Thou?" is a 2000 satirical comedy-drama film written, produced, co-edited, and directed by Joel and Ethan Coen. It stars George Clooney, John Turturro, and Tim Blake Nelson, with Chris Thomas King, John Goodman, Holly Hunter, and Charles Durning in supporting roles.

The film is set in rural Mississippi during the 1930s, and it follows three escaped convicts searching for hidden treasure while a sheriff relentlessly pursues them. Its story is a modern satire which, while incorporating social features of the American South, is loosely based on Homer's epic Greek poem the "Odyssey." Some examples of this include Sirens, a Cyclops, and the main character's name, "Ulysses", which is the Roman name for "Odysseus". The title of the film is a reference to the Preston Sturges 1941 film "Sullivan's Travels," in which the protagonist is a director who wants to film "O Brother, Where Art Thou?," a fictitious book about the Great Depression.