The T-37A was a Soviet amphibious light tank. The tank is often referred to as the T-37, although that designation was used by a different tank which never left the prototypestage.The T-37A was the first series of mass-produced fully amphibious tanks in the world.

The tank was first created in 1932, based on the British Vickers tankette and other operational amphibious tanks. The tank was mass-produced starting in 1933 up until 1936, when it was replaced with the more modern T-38, based on the T-37A. Overall, after four years of production, 2552 T-37A’s were produced, including the original prototypes.

In the Red Army, they were used to perform tasks in communication, reconnaissance, and as defense units on the march, as well as active infantry support on the battlefield. The T-37A were used in large numbers during the Soviet invasion of Poland and in the Winter War against Finland. The T-37 A was also used by the Soviets in the beginning of the Great Patriotic War, but most of them were quickly lost. Surviving tanks of that type fought on the front lines until 1944, and were used in training and auxiliary defense until the end of World War II.