McCourt was born in Brooklyn, New York. In childhood, he came with his parents to Limerick, Ireland. In 1952 he went back to the USA. He has four children: Siobhan, Malachy III, Conor ( a policeman and documentary filmmaker ) and Cormac, the last two by his second wife Diana. In 1960 he was one of the four founding members of the Manhattan Rugby Football Club.
McCourt competed in 2006 as a Green Party candidate for the office of governor of New York. After him opinion polls had seen temporarily at five percent of the vote, he scored ultimately on election day only a share of 1.0 percent. Superior winner was the Democrat Eliot Spitzer.
- A Monk Swimming. Harper Collins, London, 1998, ISBN 0-00-257019-1 ( ISBN formally wrong ). dt: The boy from Limerick. From the English by Claudia Feldmann. Argon, Berlin 1999, ISBN 3-87024-490-9.