[5] His father, Thomas, was a businessman, and his mother, Helen Cecilia O'Neill, was an emergency department nurse.

[7] In 1972, Meehan was approached by Martin Charnin to work on a musical based on the comic strip Little Orphan Annie.

[10][4] In addition, Meehan was a long-time contributor of humor to The New Yorker, including the famous short story "Yma Dream"; an Emmy Award-winning writer of television comedy; and a collaborator on a number of screenplays, including Mel Brooks' Spaceballs; a remake of To Be or Not to Be; and the family drama One Magic Christmas.

[11] Meehan went on to work with Brooks on other projects on Broadway, including The Producers, based on the 1967 film.

[10][4][12] He co-wrote the book for the production of the musical Limelight: The Story of Charlie Chaplin which ran at the La Jolla Playhouse in 2010[13] and premiered on Broadway in 2012.

[19] Reflecting on his work in an interview with The New York Observer in 1999, Meehan said "I wrote stories that were serious, very somber, trying to be in the style of William Faulkner.

"[23] In 2023 his archives were donated to The New York Public Library for the Performing Arts' Billy Rose Theatre Division.