Indian seamen in Australia formed a union in October 1945 during a strike and boycott of Dutch shipping in support of the Indonesian declaration of independence in August 1945. The strike was a result of Dutch shipowners threatening to transfer Indian seamen in Dutch registered ships to other Dutch ships boycotted by Indonesian crew. The Indian seamen supported the boycott which held for nine months from 1945-1946 and intermittently over four years. They received support for some weeks from the New South Wales Trades and Labour Council in the form of rations and strike pay. Due to his work in the Indian Seamen's Club in Sydney and close relationship with the strikers, CH (Clarrie) Campbell was elected Treasurer and was the sole European office bearer. After 1947, many of the Union's functions were taken over by the Indian Seamen's Union.

The first seamen’s unions in Australia were formed in Melbourne (1872) and in Sydney (1874). In 1876 the Melbourne Seamen’s Union and the Sydney Seamen’s Union amalgamated and, by 1880, there were seamen’s unions in all the eastern and south-eastern colonies of Australia as well as in several ports in New Zealand. The Federated Seamen's Union of Australasia was registered in 1906 under the Commonwealth's industrial relations legislation and, in 1907, Head Office was transferred from Melbourne to Sydney. Although the Federated Seamen's Union of Australasia was deregistered in 1925, in 1930 many of its members went on to form the Seamen's Union of Australasia which, in 1943, became the Seamen’s Union of Australia. Despite amalgamations with the Marine Cooks, Bakers and Butchers' Association of Australia in 1983, the Federated Marine Stewards and Pantrymen’s Association of Australasia in 1988 and the Professional Divers' Association in 1991, it remained the Seamen's Union of Australia until 1993 when it amalgamated with the Waterside Workers' Federation to form the Maritime Union of Australia.