Born Michael Sinnott in Richmond Ste-Bibiane Parish, Quebec, he was the son of Irish Catholic John Sinnott and Catherine Foy, married 1879 in Tingwick, Québec. The newlyweds moved the same year to Richmond, where John Sinnott was hired as a laborer. By 1883, when Michael's brother George was born, John Sinnott was working in Richmond as an innkeeper; he worked as an innkeeper for many years afterward. John Sinnott and Catherine Foy had all their children and raised their family in Richmond, then a small Eastern Townships village. At that time, Michael's grandparents were living in Danville, Québec. Michael Sinnott moved to Connecticut when he was 17 years old.