These are the rivers with the largest drainage areas in the Oceania. In fact, all of them are in Australia.
The Murray–Darling–Culgoa–Balonne–Condamine river system, also the longest river in Australia, drains from an area of 1,061,000 km2, an area equivalent to the size of the states of Victoria and New South Wales combined, and flows eventually to the Southern Ocean.
The Warburton–Georgina river system follows, draining from an area of 365,000 km2 and flowing out to Lake Eyre. The Flinders River is the longest river in Queensland, Australia , and drains from an area of 109,000 km2.