Mount Ossa, Mountain summit in Cradle Mountain-Lake St Clair National Park, Tasmania, Australia.

Mount Ossa is the highest mountain in Tasmania, rising 1,617 metres in the Pelion Range of Cradle Mountain-Lake St Clair National Park. Its summit is bare, vertically fractured grey rock with a blocky, uneven crest, snow lying in hollows and ledges, and dark green scrub and brownish boulders at the base.

Geologist Charles Gould named the peak in the 1860s, following the fashion of the time for classical Greek place names in Tasmania. Its status as the state's highest point was only confirmed through aerial survey methods decades later, when precise measurements resolved earlier uncertainty.

The Mount Ossa highland area spans the boundary between the Big River and Northern Tasmanian Aboriginal nations. Stone tools and campsites have been found at Pelion to the north and around Lake St Clair to the south. The peak's name comes from Mount Ossa in Greece, following the classical Greek naming theme set by early surveyor George Frankland.

The climb begins at Pelion Gap where the trail is clearly marked and requires about three hours to reach the summit and return. The route crosses rocky ground and steep sections, so sturdy boots and basic fitness help make the walk safer and more comfortable.

Mount Ossa's summit is capped with Jurassic dolerite, the same hard rock found across much of Tasmania's high country. The peak was first surveyed by Charles Gould in the 1860s, but its height was not confirmed until an aerial survey in 1954. In 1991, 30 per cent of Overland Track walkers made the side trip to the summit.