John Patrick Shanley was born in The Bronx, New York City, to a telephone operator mother and a meat-packer father. He is a graduate of New York University, and is a member of the Ensemble Studio Theatre.

For his script for the 1987 film, Moonstruck, Shanley won the Academy Award for Best Original Screenplay and the Writers Guild of America Award for Best Screenplay Written Directly for the Screen.

In 1990, Shanley directed his script of Joe Versus the Volcano. Shanley also wrote two songs for the movie: "Marooned Without You" and "The Cowboy Song."

In 2004 Shanley was inducted into the Bronx Walk of Fame.

In 2005, Shanley's play Doubt: A Parable was awarded the Pulitzer Prize for Drama and the Drama Desk Award and Tony Award for Best Play. Doubt: A Parable, is featured in The Fourth Wall, a book of photographs by Amy Arbus in which Shanley also wrote the foreword.

In 2008, Shanley directed a film version of Doubt starring Meryl Streep, Philip Seymour Hoffman and Amy Adams.