Hartnett Falls is a waterfall on the Mersey River in Tasmania's central highlands, situated between Cradle Mountain and the Walls of Jerusalem National Parks.

The falls are named for Paddy Hartnett, a notable local character, and a nearby track also bears his name.

The falls are most commonly visited as part of multi-day wilderness routes, including the Overland Track and the challenging "Never Never" route, which follows the Mersey River from Junction Lake through remote alpine and rainforest terrain.

One video description notes the drop is approximately 15 metres.

The surrounding area also features other waterfalls along the Mersey River, including Clarke Falls and McCoy Falls, making the corridor a notable destination for waterfall enthusiasts and experienced bushwalkers.