Pavel Borisovich Axelrod (Russian: Па́вел Бори́сович Аксельро́д; 25 August 1850 – 16 April 1928) was a Russian revolutionary, Marxist theoretician, and a leader of the Mensheviks. Originally a follower of the anarchist Mikhail Bakunin, he converted to Marxism in the early 1880s and became a co-founder, alongside Georgy Plekhanov, of the first Russian Marxist organization, the Emancipation of Labour group, in 1883.
Following the 1903 split in the Russian Social Democratic Labour Party (RSDLP), Axelrod emerged as the foremost ideologist of the Menshevik faction. He formulated the main tenets of Menshevism, arguing for the creation of a broad-based, mass workers' party in contrast to Vladimir Lenin's concept of a narrow, centralized vanguard party. He emphasized the importance of the proletariat's political self-activity (samodeiatel'nost) and insisted that the party must follow, not dictate to, the working class.