​ROEBOURNE, a settlement of De Witt county, Western Australia, 8 m. from the N.W. coast, on the Harding river, 920 m. direct N. of Perth. It is the centre of one of the richest and most varied mineral districts in the colony; gold, silver, tin, lead, copper, diamonds and other precious stones are found. There are extensive pearl fisheries off its port at Cossack Bay.