The Australian Communist Party established on 28th of June 2019, after analysing the marked inadequacy of the parties of the left and deciding on a new path in the movement for socialism in Australia.

The ACP was originally founded on the 30th of October, 1920. It was a direct outcome of the successful Bolshevik revolution in Russia and at the same time the culmination of the struggles of the Australian labour movement since 1890. Although in its first decade the CPA conducted some important campaigns of international solidarity (with the British General Strike and against the execution of Sacco and Vanzetti, for example), domestically the Party failed to fulfill its potential due to a predominance of right opportunist ideas amongst the Party leadership.

Nevertheless, the ruling class tried to ban the Party in 1926, a move that was only finally defeated in the courts in 1932. In 1929, the election of a new leadership signalled the defeat of the right opportunists and the CPA embarked on a vigorous program of industrial organising. Within 12 months the Party's membership grew fourfold. The CPA led campaigns to organise the unemployed, coal miners, wharf-labourers, iron workers, seamen, railway workers, firefighters, and many more. On the basis of their militant work on behalf of the working class, communists were elected to the leading positions in numerous major trade unions.

Throughout the 1930s, the CPA also led the fight against war and fascism. Australian volunteers fought and died in the International Brigade defending Republican Spain. The Party at the same time actively developed working class cultural organisations including New Theatre (the longest-surviving working class theatre in the world). Under Party leadership organisations were set up of writers and artists. Australian folk music was rescued from oblivion. Many intellectuals joined the Party at this time or were strongly influenced by it.

The CPA assisted the emerging struggle of the Aboriginal and Torres Strait Islander people and developed policies on the national question in Australia. Immediately before World War II, attempts were made to outlaw the Party. These moves were defeated in the courts, but once the war began, the Party was banned under National Security Regulations. The Party had to work underground until the Labour government was forced to lift the ban in 1942. By then the work of the CPA in support of the war effort against Nazi Germany and imperialist Japan, together with the stunning defence efforts of the Soviet people and the Red Army, had made the continuation of the ban untenable.

The Party emerged from the period of illegality with more members than it had when it was banned. Throughout the War, the Party maintained and extended its organisation within the armed forces. By the end of the Second World War the CPA had in excess of 20,000 members (in a country with a population of five million). Efforts to ideologically destabilise the CPA continued throughout the 1950s but especially in the aftermath of the 20th Congress of the CPSU and the events in Hungary.

The extremely restricted mass media in Australia maintained an unrelenting propaganda blitz on the Communists. In the 1960s, the leadership of the CPA began to seriously lose its way. It began to downplay the role of the working class and Marxism-Leninism was relegated as being "outdated". Democratic centralism was jettisoned as an organisational principle of the Party. While Party membership and influence steadily declined and trade union leadership positions were lost, the CPA leadership adopted a hostile attitude to the international communist movement and especially to the Soviet Union. Eventually, in December 1971, a new party was formed from the ranks of the Marxist-Leninists. It took the name Socialist Party of Australia but saw itself as a "continuer" of the best policies and practices of the old CPA, while rejecting the revisionist ideology and policies of the leadership of that party.

The SPA attracted many of the workers and trade union leaders who had been members of the CPA. The SPA adopted policies dealing with the many current issues facing the working people: workers' conditions and trade union rights, the environment, peace, democratic rights, migrant rights, full equality for women. The SPA argued for land rights for Aboriginal and Torres Strait Islander people as national minorities. The party advanced the concept of a two-stage transition to socialism in Australia and called for the formation of a "left and progressive" alliance. In 1989 the remaining members of the CPA voted to liquidate the party and establish the New Left Party intended to appeal to "broad left" forces. The party formally disbanded in 1991. The New Left Party also failed and soon disbanded. In 1990, the SPA held a special congress to consider the overthrow of socialism in the Soviet Union and eastern Europe. The Party reasserted its belief in socialism and in the validity of Marxism-Leninism. The Congress declared that it was not socialism that had failed but some individual leaders who had failed to apply Marxism-Leninism correctly in their work.

At the SPA's 8th National Congress in October 1996, the Party decided to reclaim its name and was renamed the Communist Party of Australia. This proved to be a popular move both with the Party's members and in wider left circles. However, unresolved issues regarding the Party’s work in the trade unions and with the Australian Labor Party eventually resurfaced and combined with lax recruitment practices and general ill-discipline to produce an unworkable environment for committed Communists. It was these regrettable circumstances that led the founders of the Australian Communist Party to re-establish a Marxist-Leninist party in Australia.