Alexander Martinov (1865 – 1935) was a Menshevik before the Russian revolutions of 1917, and for a few years after the revolution an opponent of the Soviet government.

During 1901-2 Martinov was active on the journal of the Economist faction of the RSDLP, Rabocheye Dyelo publishing articles strongly criticised by Lenin in What Is To Be Done?

He joined the Communist Party in 1923 as an opponent of the "Left Opposition." He was a chief architect of the "bloc of four classes."

Martinov was an advocate of the two stage theory, that a fully capitalist government was needed to run well into its course before Socialism and thereafter Communism could be possible.