The Australian Council of Trade Unions (ACTU) is the largest peak body representing workers in Australia. It is a national trade union centre of 46 affiliated unions.
The ACTU was formed in 1927 as the "Australian Council of Trade Unions". It was one of the earliest attempts by trade unions to apply the principles of One Big Union earlier explored by more radical syndicalist unions like the CNT or revolutionary industrial unions like the IWW.
In the Australian case, agitation for One Big Union occurred from 1911 from two different sectors: from the revolutionary Australian section of the IWW and from the pro-arbitration Australian Workers Union (AWU). At that time the AWU was the largest single Australian union. In 1918 after the collapse of the Australian IWW, a group of militant trade unions (which were opposed to the AWU) attempted to form One Big Union under the name Workers Industrial Union of Australia (WIUA). The hostility between the WIUA and the AWU prevented the formation of One Big Union in Australia. It was the attempts of Stanley Bruce's federal government in 1927 to dismantle the Australian Industrial Relations Commission which impelled the Australian trade unions to form a national council.