The Royal Oak Hotel is a pub located in Balmain, a suburb in the inner west region of Sydney, in the state of New South Wales, Australia.

The pub has historical links with the union movement and is one of a number of buildings which formed an integral part of the shipbuilding and industrial history of the local area.

The land on which the pub currently stands was part of a much larger 220-hectare (550-acre) grant to colonial surgeon Dr William Balmain made in 1800 by Governor John Hunter.

By the mid-1860s, nearby Mort's Dock was undertaking heavy industrialisation of its site in Balmain and was a generator of much housing and employment in the local area.

In 1887 the Balmain branch of The Slip, Dock and General Labourers Union was formed and the mailing address was given as Clifford's Hotel.