In the communist or Marxist-Leninist movement, an anti-revisionist is one who favors a strict interpretation of Marxist-Leninist doctrine. The term is generally seen as positive with its opposite revisionism usually used pejoratively. The original sense of the term was used at the beginning of the twentieth century during the split between Communist groups and democratic socialists, who believed that Marx's ideas should be revised to allow for the possibility of social progress without revolution.

The term itself is usually controversial among Marxist-Leninist as groups labelled as revisionist tend to deny the label and argue that they are indeed following the ideas of Marx. Often they will then accuse self-proclaimed anti-revisionist groups as left deviationist.

The term has been used to refer to those who held to a hard-line Stalinist or Maoist position, and who opposed the reforms initiated in some communist countries by leaders like Nikita Khrushchev in the Soviet Union, and Josip Broz Tito in Yugoslavia.

During the Sino-Soviet split, the governments of the People's Republic of China under Mao Zedong and Albania under Enver Hoxha proclaimed themselves as taking an anti-revisionist line and denounced Khrushchev. In the United States, those who supported China or Albania during the Sino-Soviet split were expelled from the United States Communist Party under orders from Moscow, and in 1962 they formed the Progressive Labor Party. Several other small Stalinist or Maoist political parties in the United States, such as the Revolutionary Communist Party, are also see themselves as anti-revisionist.

Today, the government of Kim Jong-Il in North Korea is often referred to as adhering to an anti-revisionist variety of Marxism-Leninism.