The project was initiated by the Red Army's need to replace the aging five-turreted T-35 tank based on combat experience in the Spanish Civil War.

The T-100 was in direct competition against the very similar SMK heavy tank, by Lt-Colonel Josef Kotin's team at the Leningrad Kirovsky Factory.

The multi-turret concept, usually a mix of cannon and machine gun turrets, had been common in the 1920s, with the British one-off Vickers A1E1 Independent influencing the Soviet T-35.

It was never put into production, due to the archaic design concept, poor mobility and the availability of a far superior alternative, the KV series.

SU-100Y – In an attempt to rush into use a tank armed with a large howitzer capable of dealing with Finnish bunkers, one of the T-100s was converted into the SU-100Y self-propelled gun.