Born into a family that was steeped in the traditions of the game of hurling, his grandfather and namesake, Michael Mackey, was involved in the promotion of Gaelic games even before the establishment of the Gaelic Athletic Association in 1884.
Mackey was married to Kathleen "Kitty" Kennedy (1914-2003) and the couple had five children: Paddy, Michael, Greg, Audrey and Ruth.