The Communist Workers' Party of Germany was an anti-parliamentarian and left communist party that was active in Germany during the Weimar Republic. It was founded in 1920 in Heidelberg as a split from the Communist Party of Germany (KPD). Originally the party remained a sympathising member of Communist International. In 1922, the KAPD split into two factions, both of whom kept the name, but are referred to as the KAPD Essen Faction and the KAPD Berlin Faction.

The Communist Party of Germany was a major far-left political party in the Weimar Republic during the interwar period, an underground resistance movement in Nazi Germany, and a minor party in West Germany during the postwar period until it was banned by the Federal Constitutional Court in 1956.