Countries that used the AT-6: Britain, Canada, France, Italy, Japan, Netherlands, New Zealand, South Africa, Southern Rhodesia, Soviet Union, Sweden, and the United States.
RAF and Commonwealth
The RAF and Commonwealth air forces used >5,000 AT-6 for training, which they called the Harvard.
The final British pilot to qualify in a Harvard was on March 23, 1955.
In the Korean War some AT-6s were used as observation planes.