His younger brother Dennis Flynn (birth name was Denis Christopher O'Flynn) was also active in Canadian politics serving as the mayor of Etobicoke, Ontario and Chair of Metropolitan Toronto.
Flynn was born Patrick Joseph "Joe" O'Flynn in Rathcormac, County Cork, Ireland on September 8, 1921.
Mr. Flynn left the hospital to pursue a career in sales and successfully represented companies such as Merrel, Alberta Distillers, and Hiram Walker.
In early 1974 he won the nomination of the Kitchener Center Liberal Party to run as their candidate for Member of Parliament in the July 8th general election.
In September 1978 he suffered a near-fatal aortic aneurysm while a patient in the National Defence Medical Centre in Ottawa.
In May 1979 Prime Minister Pierre Trudeau recommended to the Governor General Ed Schreyer that he be appointed to the Canadian Pension Commission for a 10-year period.