The Third Intercolonial Trades Union Congress was a meeting of trade union delegates held in Sydney, Australia in October 1885, succeeding congresses in 1879 and 1884. It was the first of these congresses to have representatives from every colony, except Western Australia, and every trade and industry.
This congress was a pivotal event in the history of trade unions, as it brought together representatives from all Australian colonies, with the exception of Western Australia, to discuss and address common issues affecting various trades and industries.