William J. O'Donnell was from Philadelphia, Pennsylvania. He joined the Army Air Corps in 1940. He, like most fighter pilots, had always had a yearning to fly. As a teenager he went through a Civilian Pilot Training programme and and obtained a Private Pilot's License. He then waited until he was old enough to become an Aviation Cadet and applied, with 13 others, for admittance to that programme. He was the only one of the group to pass the physical examination and was enlisted in December 1940. Upon graduation at Craig Field, Selma, Alabama, he received his commission and wings and became an instructor in single engine advanced raining. In October 1944 he went overseas to England as a captain and was assigned to the 4th fighter Group, 335th Squadron. He flew a full tour with 63 combat missions and then transferred to the 336th squadron as Squadron Commander, the first of seven squadrons he would eventually command prior to his retirement.

Colonel O'Donnell had 4.5 enemy aircraft destroyed (1.5 air + 3 ground) to his credit when the war ended.

Commanded the 36th FBS in Korea flying F-51Ds and F-80s on 112 combat missions.

Retired has Lt Col 1961.