William "Gatz" Hjortsberg (born 1941, New York, New York) is a novelist and screenwriter best known for writing the screenplays of the movies Legend and Angel Heart.
His novel Falling Angel was the basis for the film Angel Heart (1987) (released in French-speaking Canada under the title Aux portes de l'enfer).
- Hjortsberg, William (2012). Jubilee Hitchhiker: The Life and Times of Richard Brautigan. Counterpoint Press. ISBN 9781582437903.