[1] It gets the common name hammer octopus from a modified arm possessed by males and used in reproduction.

[7][2] It was first described by William Evans Hoyle[8] in 1885,[6] based on a specimen found in Port Jackson in New South Wales.

[7][2] O. australis is found in coastal waters and bays[5] along the eastern coast of Australia from central Queensland to southern New South Wales,[3] most commonly in subtropical inshore waters, and from depths of around 3 to 140 meters.

[5] It tends to live on sand or mud seafloors,[11] among sponges, ascidians, or mollusks, or in seagrass.

[10] The diet of O. australis is mostly composed of isopods,[12] but they also eat other types of crustaceans, other octopuses, bristle worms, gastropods, and bivalves.