Golden Gate Highlands National Park is located in Free State, South Africa, near the Lesotho border. It covers an area of 340 km² (130 sq mi). The park's most notable features are its golden, ochre, and orange-hued, deeply eroded sandstone cliffs and outcrops, especially the Brandwag rock. Another feature of the area is the numerous caves and shelters displaying San rock paintings. Wildlife featured at the park includes mongooses, eland, zebras, and over 100 bird species. It is the Free State's only national park and is more famous for the beauty of its landscape than for its wildlife. Numerous palaeontology finds have been made in the park, including dinosaur eggs and skeletons.

"Golden Gate" refers to the sandstone cliffs found on either side of the valley at the Golden Gate dam. In 1875, a farmer called J.N.R. van Reenen and his wife stopped here as they travelled to their new farm in Vuurland. He named the location "Golden Gate" when he saw the last rays of the setting sun fall on the cliffs.

In 1963, 47.92 km² (11,840 acres) was proclaimed as a national park, specifically to preserve the scenic beauty of the area. In 1981, the park was enlarged to 62.41 km² (15,420 acres), and in 1988, it was enlarged to 116.33 km² (28,750 acres). In 2004, the park was announced to be joining with the neighbouring QwaQwa National Park. The amalgamation of QwaQwa National Park was completed in 2007, increasing the park's area to 340 km² (84,000 acres).

The park is 320 km (200 mi) from Johannesburg and is close to the villages of Clarens and Kestell, in the upper regions of the Little Caledon River. The park is situated in the Rooiberge of the eastern Free State, in the foothills of the Maluti Mountains. The Caledon River forms the southern boundary of the park, as well as the border between the Free State and Lesotho. The elevation ranges from a 1,800 m (5,900 ft) plateau in the north to heights of 2,700 m (8,900 ft) in the south. The highest peak in the park (and also in the Free State) is Ribbokkop at 2,829 m (9,281 ft) above sea level.

The park is located in the eastern highveld region of South Africa and experiences a dry, sunny climate from June to August. It has showers, hail, and thunderstorms between October and April. It has thick snowfalls in the winter. The park has a relatively high rainfall of 800 mm (31 in) per year.

The park is an area of rich highveld and montane grassland flora. It has more than 60 grass species and a large variety of bulbs and herbs. Each of these species has its own flowering time, meaning that veld flowers can be seen throughout the summer. The park also has Afromontane forests and high-altitude Austro-Afro alpine grassland, which is scarce in South Africa. The ouhout (Leucosidea sericea), an evergreen species, is the most common tree in the park. Ouhout is a favourite habitat of beetles and 117 species occur on these trees in the park. The Lombardi poplars and weeping willows in the park are introduced species, but are kept because of their cultural and historic connection with the eastern Free State. Other exotic species in the park, for example wattle and bluegum, are systematically eradicated.

Instead of reintroducing one of the "big five" into the park, the sungazer lizard and water mongoose were reintroduced. Twelve species of mice, 10 species of carnivores, and 10 antelope species have been recorded in the park. The grey rhebok and the mountain reedbuck were present when the park was established.

Over 210 bird species have been observed in the park, including the rare bearded vulture and the endangered Cape vulture and bald ibis.