When the 85-millimeter cannon was adapted to the medium tank T-34 to form the new T-34/85 it became mandatory to increase the firepower of the medium self-propelled cannon installed in the same chassis. The SU-85 could no longer be considered as an effective support vehicle for the medium tank. In 1944 the SU-85 started to be replaced by the more powerful SU-100, which was very similar to its predecessor, but armed with the 100-millimeter cannon D-10S Model 1944, projected by the team led by General F. F. Petrov. This cannon was adapted from the dual-purpose high-velocity naval cannon 100/56.

The SU-100 started to be produced in September 1944 in Uralmashzavod. At the end of the year around 500 exemplars had been delivered to the units of the Red Army, and at the end of the war 1800 had been produced. The SU-100 proved to be very effective to destroy the German heavy tanks and tank destroyers, such as the Panther, Tiger, Ferdinand, Jagdpanther or Jagdtiger. It had a very relevant role during the final phase of the Second World War. As in the SU-85 the cannon was installed in the frontal part of a fixed armored superstructure, along with a periscope, and secondary armament did not exist.

Differently to the T-34 tank in which the SU-100 was based, the driver was separated from the rest of the crew members by an armored plate, so that an internal communication system was necessary. The 100-millimeter cannon had very improved prestations in respect of the 85-millimeter cannon, firing 16-kilogram high-explosive projectiles or 19.5-kilogram fragmentation projectiles at a maximum distance of 19200 meters. Apart from its characteristic long cannon, the SU-100 was different from its predecessor in some external characteristics, including the shape of the cannon shield and the cylindrical cupola "attached" to the right side of the superstructure.

In 1944 the self-propelled cannon SU-100 was put into service in the Soviet Army and three decades later it was still in use in many countries of the Eastern Bloc and Middle East. The SU-100 became the standard support element for the armored and mechanized divisions until the reorganization of 1957, when it was replaced by the SU-122 based on the chassis of the heavy tank IS-2. After the war, deprived of their cannons, both the SU-85 and the SU-100 were used as command and rescue armored vehicles. The holes left by the removed weapons had to be properly filled with armored plates. In total 750 units were built.