Anti-communism is political and ideological opposition to communist beliefs, groups, and individuals. Organized anti-communism developed after the 1917 October Revolution in the Russian Empire, and it reached global dimensions during the Cold War, when the United States and the Soviet Union engaged in an intense rivalry. Anti-communism has been an element of many movements and different political positions across the political spectrum, including anarchism, centrism, conservatism, fascism, liberalism, nationalism, social democracy, socialism, leftism, and libertarianism, as well as broad movements resisting communist governance. Anti-communism has also been expressed by several religious groups, and in art and literature.

Communism is a left-wing to far-left sociopolitical, philosophical, and economic ideology within the socialist movement, whose goal is the creation of a communist society, a socioeconomic order centered around common ownership of the means of production, distribution, and exchange that allocates products to everyone in the society based on need. A communist society would entail the absence of private property and social classes, and ultimately money and the state.