Joseph William Stefano (May 5, 1922 – August 25, 2006) was an American screenwriter, known for adapting Robert Bloch's novel as the script for Alfred Hitchcock's film Psycho, and for being the producer and co-writer of the original The Outer Limits television series.

In possession of a large collection of sheet music, he once spent five hours challenging pianist Michael Feinstein on the titles of obscure Tin Pan Alley songs.

Stefano began writing movie scripts in the late 1950s, firstly for Martin Ritt with The Black Orchid (1959); his mother's occupation was an influence on the screenplay.

Stefano was offered the task of scripting Hitchcock's The Birds (1963) and Marnie (1964), but was already committed to produce and write for his friend Leslie Stevens' science fiction television anthology series The Outer Limits.

Stefano was one of the Guests of Honor at the 1974 NY Telefantasy Convention (along with Noel Neill, Jim Danforth and William Tuttle), and spent hours signing autographs for hundreds of Outer Limits fans.