Democratic centralism is a Communist organizational doctrine that defines the methods of decision making and governance. It was conceived by Lenin and defined in his tract, "What is to Be Done?", written prior to the Russian Revolution. The doctrine was intended to ensure that the Bolshevik Party was an effective revolutionary organization. The doctrine is still used today, in one form or another, by many political parties that define themselves as Leninist.

As Lenin described it, democratic centralism consisted of "freedom of discussion and criticism, unity of action". The democratic aspect of this methodology describes the freedom of members of the political party to discuss and debate matters of policy and direction; but once the decision by the party was made (by majority vote), all members were expected to follow that decision unquestioningly. This latter aspect represented the centralism. The doctrine of democratic centralism served as a source of the split between the Bolsheviks and the Mensheviks, who supported a looser party discipline, within the Russian Social Democratic Labor Party in 1903.

After the successful consolidation of power by the party, the Bolshevik leadership instituted an ostensibly "temporary" ban on factions within the party in 1921. This precipitated the end of the "democratic" element of democratic centralism within the party membership, and with the rise of Stalin to a position of absolute power within the party (and the Soviet Union), there was no freedom of discussion within the party, except by members of the ruling party Politburo.