Stapleton was born in Troy, New York, the daughter of Irene (née Walsh) and John P. Stapleton, and grew up in a strict Irish AmericanCatholic family.[1][2] Her father was an alcoholic and her parents separated during her childhood.[3][4] She had a brother, Jack. Stapleton began acting in theater after finishing high school and rapidly gained respect as both a dramatic and comedic actress.
Stapleton's first husband was Max Allentuck, general manager to the producer Kermit Bloomgarden, and her second, playwright David Rayfiel, from whom she divorced. She had a son, Daniel, and a daughter, Katherine, by her first husband. Her daughter, Katherine Allentuck, garnered good reviews for her single movie role, that of "Aggie" in Summer of '42 (Stapleton herself also had a minor, uncredited role in the film as the protagonist's mother).
Stapelton suffered from anxiety and alcoholism for many years and once told an interviewer, "The curtain came down and I went into the vodka."[5] She also said that her unhappy childhood contributed to her insecurities. In 2006, Maureen Stapleton, who was a heavy smoker, died of chronic obstructive pulmonary disease at her home in Lenox, Massachusetts, at the age of 80.[5]