USS O'Callahan (FF-1051) was a U.S. Navy Garcia-class destroyer escort, later reclassified as a frigate. She was named for Chaplain Lieutenant Commander Joseph T. O'Callahan, a World War II Medal of Honor recipient for his rescue of crewmen on the aircraft carrier Franklin after it was hit and severely damaged by enemy bombs.

The Defoe Shipbuilding Company was a small ship builder established in 1905 in Bay City, Michigan, United States. It ceased to operate in 1976 after failing to renew its contracts with the United States Navy. The site of the former company is now being developed for business and housing on the bank of the Saginaw River.