Joseph Cyr was the son of Albert and Antoinette Cyr. His name at birth was Gerald Joseph Cyr. Gerald Joseph Cyr was born in Old Town, Maine on 10 May 1924. At some point, he started using Joseph Gerald Cyr as his name.

Gerald Joseph Cyr enlisted in the Army Air Corps in November of 1942. served with the 453rd Bomb Group, 735th Bomb Squadron. He was the bombardier on the Lillie Bell (42-52191), a B-24 Bomber. The Lillie Bell was lost in North Sea on return flight from a mission into Germany on 6 Mar 1944. The plane was badly damaged, lost fuel, and could not make it back to England. From a crew of ten, the bombardier Lt Gerald Joseph "Joe" Cyr was the sole survivor and gave a personal account of the ditching. The home base of the 453rd Bomb Group was Old Buckenham Field, England.

According to the Maine Marriage Records, Joseph G Cyr married Marion Roma on 28 Jun 1945 in Old Town, Maine.