Francis Patrick Duffy was born on May 2, 1871, at Cobourg, Ontario, a United Empire Loyalist settlement, to which his widowed grandfather, Patrick Duffy, emigrated about 1845 from Carrickmacross, County Monaghan, with his five children, one of whom was also named Patrick. To this same Cobourg, at the height of the famine emigration, came his maternal grandparents, Thomas and Mary (Buckley) Ready of Kings and Roscommon. Both families worked long hours in the woolen mills at wretched wages. There they became acquainted, and Patrick Duffy and Mary Ready were married in St. Michael's Catholic Church in 1866. Settling down to a restricted life of laborious poverty, they had eleven children, six of whom lived to maturity. The third child was Francis Patrick, whose frail health freed him from hard labor and committed him to studies and ultimately to the priesthood.