Mary Hackett was born in 1906 in New York City. Her father Cleveland Moffett was a writer and journalist, author of children’s books and mysteries, and an editor at the Paris Herald. She attended Brearley and Lincoln schools and briefly Cornell University, but she never had any formal art training.
In 1926 in Paris she married Chauncey Hackett, a Washington, D.C., lawyer. They had three children, Wendy, Thomas and Patrick. In the early 1930s the Hacketts visited Provincetown for the first time. After several summers renting various houses around town they bought the house on Nickerson Street where she lived until her death.
From the 1930s on she showed regularly at the Provincetown Art Association and during the 1940s at Don Witherstines’ Shore Studios in the West End. In 1970 she had a show at the studio of Jack Gregory on Nelson Avenue. In 1981 she had a large retrospective at the Provincetown Art Association and Museum and another in 1987 at the Chandler Gallery in Wellfleet. She was included in the Long Point Gallery invitational “75:A Celebration” in 1989. She died in September of 1989.