The Communist Party of Australia (CPA) was an Australian political party founded in 1920. The CPA achieved its greatest political strength in the 1940s. It was banned temporarily in 1940 and faced an attempted ban in 1951 before dissolving in 1991.

Its youth wing worked under several different names at different times, including the Young Communist League (YCL); the Young Comrades Club (YCC); the League of Young Democrats (LYD); the Eureka Youth League (EYL); and lastly the Young Socialist League, which in 1984 became part of the Left Alliance.