Jonathan Michael Gavin is a fictional character on the FX drama Rescue Me. The character is played by Charles Durning. Michael Gavin is a retired New York City Fire Department Firefighter and a World War II veteran.
Michael (earlier called John) and his wife Martha have six children together (Tommy Gavin, a New York City Firefighter, Johnny Gavin, a New York City Police Detective, Maggie Gavin, Rosemary Gavin, Timo Gavin and an unnamed sibling, most likely a brother). Michael also has a son named Liam Murphy with his mistress of 36 years, a fact he keeps hidden until Liam tracks Tommy down and tells him. Michael suspects he is also the father of his mistress' older daughter Mariel, but this is later revealed to be incorrect after Mariel has a DNA test done.
He embraces the bachelor lifestyle after leaving his wife Martha, who eventually passes away. He then marries an elderly Korean woman named Jenny Ng. Later in season 2, when his second wife dies and is partially eaten by the cats, Michael believes he has struck it rich. However, he learns that his wife left all of her money to her cats, leaving him with only $50,000. In season 3, he is showing signs of Alzheimer's disease, which worries Tommy. In the beginning of Season 3, he moves in with Tommy. At the end of Season 3, he moves in with Lou's uncle, with whom he served in the FDNY and in whom he finds a kindred spirit.
In Season 4, Michael joins Tommy and the other Gavins in staying sober and even makes a good run of it, although he admits that he cannot stop thinking about drinking and women. At a minor-league baseball game with Tommy, Michael quietly passes away in his seat. His ghost however, continues to appear to Tommy in Seasons 5, 6, and 7.