Sundown National Park, Nature reserve in Tenterfield Shire Council, Australia.

Sundown National Park is a nature reserve in the Tenterfield Shire Council area of southern Queensland, close to the New South Wales border. The terrain is shaped by steep ridges and deep valleys cut through by rivers, cliff faces, and dense bushland.

Before becoming a national park, the land was mined for molybdenite, arsenic, tungsten, copper, gold and tin; the disused mines remain contaminated and access to them is restricted. Some areas were also cleared for sheep grazing and wool production. The park was officially designated in 2009.

The park's name comes from the former Sundown pastoral station on whose land it was created. Grazing for wool and small-scale mining for molybdenite, arsenic, tungsten, copper, gold and tin shaped the land before protection; disused mine workings remain, and access to them is restricted because of contamination.

The main camping area at Broadwater has basic facilities, but overnight stays require advance permission, so plan ahead. The terrain is remote and trails can be demanding, so good footwear and enough water are worth bringing along.

The park holds Australia's northernmost population of wombats, making sightings here possible in a region where they are otherwise rarely found. Over 150 bird species have been recorded within the park, which makes it one of the better spots for birdwatching in this part of the country.