The history of ocean renewable energy developments in Australia is reviewed. A layperson’s description of the physical operating principle is given for the main classes of technology that have been tested in Australian waters. The Australian marine domain possesses among the world’s most energetic wave-energy resources, driven by powerful mid-latitude westerly winds. The northern coast of Western Australia has tidal ranges significant on a global scale, and some geographical features around the continent have local tidal resonances. The East Australian Current, one of the world’s major western boundary currents, runs along the eastern Australian seaboard, offering potential for ocean-current energy. Sea-water temperatures in the tropical north-east of Australia may permit ocean thermal energy conversion. While this abundance of resources makes Australia an ideal location for technology development, the population is highly concentrated in a few large cities, and transmission infrastructure has developed over a century to supply cities from traditional power plants. Several wave-power developments have resulted in demonstration of deployments in Australian waters, three of which have been grid connected. Trials of tidal devices have also occurred, while other classes of ocean renewable energy have not yet been trialled. The prospects for marine renewable energy in Australia are discussed including non-traditional applications such as coastal protection and energy export.