What is the highest mountain on the Australian mainland?

The highest mountain on the Australian mainland is Mount Kosciuszko, rising 2,228 metres above sea level.

It stands in the Main Range of the Snowy Mountains in New South Wales, within Kosciuszko National Park. Polish explorer Paweł Edmund Strzelecki reached the summit on 12 March 1840 and named it after Polish military leader Tadeusz Kościuszko.

A famous mapping error temporarily swapped the names of Kosciuszko and nearby Mount Townsend, Australia’s second-highest mountain. Historical research later confirmed that the original name belonged to the higher summit.

The answer applies specifically to mainland Australia. Australia-administered Heard Island has the higher Mawson Peak, while Puncak Jaya in New Guinea is higher if “Australian continent” is defined geographically rather than politically. The summit is accessible by a relatively straightforward walking track from Thredbo or Charlotte Pass.