Moran was born in Yuba City, California, but his family moved frequently because his father was a United States Army officer. While his family was living in Cedar Grove, New Jersey, he graduated from Passaic Valley Regional High School in Little Falls. While he was a student there, he designed and supervised construction of an elaborate set for a benefit production of Robert Merrill's musical Take Me Along. He gained some of his first experience under Gilbert Rathbun in the theater program at Seton Hall University in South Orange, N.J. - though he was not a student there - and at the Theater on the Mall in Paramus, where he worked with director Robert Ludlum, who had not yet launched his career as a novelist. Moran's roles at Seton Hall included Sir Toby Belch in William Shakespeare's Twelfth Night and "Mortimer, the Man Who Dies" in The Fantasticks by Harvey Schmidt and Tom Jones. Moran moved to the Lower East Side of New York City in 1966 and was educated at New York University's Tisch School of the Arts. He became a member of the theatre groups the Manhattan Project and the Cooper-Keaton Group. Both groups produced plays written by Moran, including Call Me Charlie, starring Danny DeVito. He also appeared in several productions for the New York Shakespeare Festival, and in off-Broadway productions including Sheridan's The Rivals, of which one critic wrote, "Michael P. Moran, built like a barrel, comes close to stealing the show as he roars and blusters through the role of Sir Anthony." Moran appeared in several plays by Horton Foote at the Ensemble Studio Theatre: The Prisoner's Song, Everything That Rises Must Converge, and The Belmont Avenue Social Club. The New York Times wrote of Prisoner's Song "Pitch-perfect performances by the four-member cast make it work.... The galvanizing force, though, is Michael P. Moran's aching rendition of Luther Wright." In 2002-2003, he portrayed Fred "Pap" Rose in the musical Hank Williams: Lost Highway by Randal Myler and Mike Harelik, based on the life of Hank Williams. The show played to a positive critical response at the Manhattan Ensemble Theatre in Soho and then at the Little Shubert Theatre in Midtown, with one reviewer writing "the cast is strong, particularly Michael P. Moran as Hank's manager Fred Rose". Moran died at the age of 59, in a New York hospital, from Guillain–Barré syndrome. He was four days short of his 60th birthday.
