Xining is the capital and most populous city of Qinghai province in western China and the largest city on the Tibetan Plateau. As of the 2020 census, it had 2,467,965 inhabitants (2,208,708 as of 2010), of whom 1,954,795 lived in the built-up (or metro) area made of 5 urban districts. The city lies in the Huangshui River Valley, also known as Tsongkha (Tibetan: ཙོང་ཁ་), and owing to its high altitude, has a cool climate on the borderline between cool semi-arid and dry winter humid continental.

Xining was a commercial hub along the Northern Silk Road's Hexi Corridor for over 2000 years, and was a stronghold of the Han, Sui, Tang, and Song dynasties' resistance against nomadic attacks from the west. Although long a part of Gansu province, Xining was added to Qinghai in 1928. Xining holds sites of religious significance to Muslims and Buddhists, including the Dongguan Mosque and Kumbum Monastery. It is connected by the Qinghai–Tibet railway to Lhasa, Tibet and connected by a high-speed railway to Lanzhou, Gansu and Ürümqi, Xinjiang.

The city is home to Qinghai University, a comprehensive university and the only Double First-Class University in Xining.

Xining has a history of over 2,100 years and was a chief commercial hub on the Hexi Corridor caravan route to Tibet, handling especially timber, wool and salt in ancient times. The trade along the Hexi Corridor was part of a larger trade corridor along the Northern Silk Road, whose use was intensified in the 1st century BC after efforts by the Han dynasty to control this route.

Under the Han dynasty (206 BC – 220 AD), a county called Linqiang was established to control the local Qiang tribesmen. It was again a frontier county under the Sui (581–618) and Tang (618–907) dynasties; during the 7th and early 8th centuries it was a center of constant warfare with Tuyuhun and Tibet. In 763, it was overrun by the Tibetans and while under Tibetan control was known to the Chinese as Qingtang cheng (青唐城). Recovered by the Song dynasty in 1104, it received the name Xining (meaning "peace in the west") and has been the seat of a prefecture or superior prefecture under that name since that time. The founder of Gelug Tsongkhapa (Tibetan: ཙོང་ཁ་པ་, meaning: "the man from Tsongkha". c. 1357–1419) was born in the 14th century, and on the site of his birthplace the Kumbum Monastery was founded in the late 16th century, establishing Xining as an important religious center for the Gelug School of Buddhists.

A major earthquake occurred May 22, 1927, measuring at a magnitude of 7.6. It was one of the deadliest earthquakes in China with a total count of over 40,000 deaths. It also caused large land fractures.

Xining was the extraterritorial capital of the Koko Nor territory and remained in Gansu until 1928, when it became the provincial capital of the newly established independent province of Qinghai.

Xining was subjected to aerial bombardment by Japanese warplanes in 1941 during the Second Sino-Japanese War. The bombing spurred all ethnicities in Qinghai, including the local Qinghai Mongols and Qinghai Tibetans, against the Japanese. The Salar Muslim General Han Youwen directed the defense of the city of Xining during air raids by Japanese planes.