The Black Swan (Cygnus atratus) is an Australian waterbird and the official state bird of Western Australia.

This bird is a member of the duck, goose, and swan family Anatidae.

Black swans are found in all states of Australia. Prior to the arrival of the Maori a sub-species, the New Zealand Swan used to live in New Zealand. This was hunted to extinction, more recently though both introductions by Europeans and probable natural migration they are established again in New Zealand. The adult bird weighs up to 20 lb (9 kg). Unlike many other waterbirds, black swans are not migratory; they spend their entire life in the area where they were clutched.

Black Swans nest on large mounds that they build in the middle of a shallow lake. They reuse the same nest each year, restoring or rebuilding it as needed. Male and female swans share the care of the nest, and once the cygnets are fledged, it is not uncommon to see whole families looking for food.