Fort Dundas was a short lived British settlement on Melville Island between 1824 and 1828 in what is now the Northern Territory of Australia. The establishment of the settlement caused the border of New South Wales to be moved west from the 135th meridian to the Western Australia border (129th meridian).
The settlement was begun in September 1824, after ships had set out from Sydney to colonise the northern part of Australia. It was named after Robert Dundas, the First Lord of the Admiralty. Colonists had bad relations with the Tiwi aborigines, tropical storms, a large distance from other settlements, and a low food supply making the efforts at settlement especially difficult. Two men were speared by aborigines. The British abandoned the effort at the fort in 1828, with the last of the settlers leaving in February 1829.
In recent years, archaeologists have excavated parts of the site.