Tjoritja / West MacDonnell National Park, Nature reserve near Alice Springs, Australia.

Tjoritja / West MacDonnell National Park is a 2,069 km² national park in the MacDonnell Ranges west of Alice Springs, Northern Territory. It stretches about 250 km along the ranges and includes Simpsons Gap, Ellery Creek Big Hole, Ormiston Gorge, Glen Helen Gorge, Redbank Gorge, the Ochre Pits and Mount Sonder. The Larapinta Trail runs east–west through the park.

The park was established in 1992 after the Northern Territory government bought 170,000 hectares from five cattle farms that had been abandoned following repeated droughts. It covers 2,069 km² of the MacDonnell Ranges west of Alice Springs. The Arrernte name Tjoritja is used for the range and the park.

The park is called Tjoritja by its Arrernte traditional owners, and the land holds great significance in Arrernte culture. At Rungutjirpa (Simpson's Gap), Arrernte tradition holds that ancestral beings at this place were giants. The Ochre Pits are among the sites along the park's 250 km length where visitors can learn about this connection to country.

The park is reached from Alice Springs by the sealed Larapinta Drive and Namatjira Drive; the route from Uluru is an unsealed track for four-wheel drives only. The 223 km Larapinta Trail passes through the park, and facilities include camping areas, caravan sites, gas barbecues and swimming spots. Carry your own drinking water, as natural sources are not reliable.

The Arrernte name Tjoritja refers to the MacDonnell Ranges, and the park's traditional owners consider the country significant in Arrernte culture. At Rungutjirpa (Simpson's Gap), Arrernte tradition holds that ancestral beings at this place were giants. The Ochre Pits are another site where mineral pigments were gathered.