Jonathan Hiatt Nicolson Dermot Irwin (born 21 June 1941), is a former blood stock agent, auctioneer, stud owner, publisher and racetrack executive. In 1997, he founded the Jack and Jill Foundation with his wife Mary Ann O'Brien, to provide home health care to severely sick babies. It was set up as a direct response to the Irwin’s experience of caring at home for their son Jack, born with severe brain damage in 1996.