The SMK was an armored vehicle prototype developed by the Soviet Union prior to the Second World War. It was named after Sergei Mironovich Kirov, a Communist Party official assassinated in 1934. The SMK was discovered and classified by German intelligence as the T-35C, this has led to the misunderstanding that the T-35 took part in the Russio-Finnish war.

Only one was built and after a trial showing the downsides of its weight and size against the KV tank and brief use in the war with Finland, the project was dropped.

The SMK's armament was a short 76.2 mm gun in the upper centrally placed turret and a 45 mm weapon in the forward turret.