A communist party is a political party that seeks to realize the socio-economic goals of communism. The term "communist party" was popularized by the title of The Manifesto of the Communist Party (1848) by Karl Marx and Friedrich Engels. As a vanguard party, the communist party guides the political education and development of the working class (proletariat). As a ruling party, the communist party exercises power through the dictatorship of the proletariat. Vladimir Lenin developed the idea of the communist party as the revolutionary vanguard, when the socialist movement in Imperial Russia was divided into ideologically opposed factions, the Bolshevik faction ("of the majority") and the Menshevik faction ("of the minority"). To be politically effective, Lenin proposed a small vanguard party managed with democratic centralism which allowed the centralized command of a disciplined cadre of professional revolutionaries. Once a policy was agreed upon, realizing political goals required every Bolshevik's total commitment to the agreed-upon policy.

In contrast, the Menshevik faction, which initially included Leon Trotsky, emphasized that the party should not neglect the importance of mass populations in realizing a communist revolution. In the course of the revolution, the Bolshevik party which became the Communist Party of the Soviet Union (CPSU) assumed government power in Russia after the October Revolution in 1917. With the creation of the Communist International (Comintern) in 1919, the concept of communist party leadership was adopted by many revolutionary parties, worldwide. In an effort to standardize the international communist movement ideologically and maintain central control of the member parties, the Comintern required that its members use the term "communist party" in their names.

Under the leadership of the CPSU, the interpretations of orthodox Marxism were applied to Russia and led to the emergence of Leninist and Marxist–Leninist political parties throughout the world. After the death of Lenin, the Comintern's official interpretation of Leninism was the book Foundations of Leninism (1924) by Joseph Stalin.