Corporal Ouellette was a medic with the 3rd Ambulance Company, 3rd Medical Battalion, 3rd Infantry Division. He was listed as Missing in Action while tending his wounded comrades in South Korea on 27 November 1950. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Ouellette was awarded the Purple Heart, the Combat Medical Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.