Yu Shan or Yushan, Tongku Saveq, Mount Niitaka (during Japanese rule), and Mount Morrison before Japanese rule, is the highest mountain in Taiwan at 3,952 m (12,966 ft) above sea level, giving Taiwan the 4th-highest maximum elevation of any island in the world. It is the highest point in the western Pacific region outside of the Kamchatka Peninsula. Yushan and its surrounding mountains belong to the Yushan Range. The area was once in the ocean; it rose to its current height because of the Eurasian Plate's movement over the Philippine Sea Plate. Yushan is ranked 40th by topographic isolation.

The mountains are now protected as the Yushan National Park. The national park is Taiwan's largest, highest, and least accessible national park. It contains the largest tract of wilderness remaining on the island.

Yushan or Yu Shan is the pinyin romanization of the Chinese name 玉山. It is also known as Mount Yu, Mount Jade, and Jade Mountain, calques of the same name. The name derives from its appearance in the winter, when its thick snow cover is thought to make its peak look like stainless jade. "Yushan" or Jade Mountain was also the name of a location in ancient Chinese mythology, a paradise said to be the home of the Queen Mother of the West.

During the Qing Dynasty, Yushan was known in Chinese as Mugangshan ("Wooded Mountain") from its surrounding forests. Other Chinese names included Batongguan, transcribing its native Tsou name "Patungkuonʉ"; Baiyushan ("White Jade Mountain"); and Xueshan ("Snowy Mountain"). It was previously known in English as Mount Morrison, a name sometimes mistakenly thought to honor the missionary Robert Morrison, but simply the name of an American captain who sighted it.

Other native names for the mountain include Saviah and Tongku Saveq (Bunun; the latter means "highest peak" or "sheltering peak"), Tanungu'incu (Kanakanavu), and Kanasian (Paiwan).

During the Empire of Japan's rule in Taiwan, the mountain became known as Mount Niitaka or Niitakayama ("New High Mountain") because new surveying showed that it was 176 m (577 ft) higher than Mount Fuji in the Japanese archipelago.

The island of Taiwan is situated at the intersection of two tectonic plates: the Eurasian Plate and the Philippine Sea Plate. Even as "recently" as the late Paleozoic (some 250 million years ago), the land here was still but a sedimentary seabed layered with silt and sand. As the two plates began pressing against each other, the land buckled, bent, and created the landscape – composed of 165 mountains higher than 3,000 m (9,800 ft) above sea level on a relatively small island (38th largest in the world).

Yushan is also notable in containing the highest point on the Tropic of Cancer and the only point on that circle of latitude where there is any evidence of Quaternary glaciation. As recently as seventeen thousand years ago, permanent ice caps existed throughout Taiwan's highest mountains and extended owing to the wet climate down to 2,800 m (9,190 ft); whereas currently, the nearest glaciers to the Tropic of Cancer are in Mexico on the Iztaccíhuatl volcano.