Shaanxi (help·info) (simplified Chinese: 陕西; traditional Chinese: 陝西; pinyin: Shǎnxī; Wade–Giles: Shan-hsi; Postal map spelling: Shensi) is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province. Shaanxi is the historical home, along with Gansu of the dialect of the Dungans, of the Hui people, who emigrated out of China to Central Asia.

By regular Hanyu Pinyin rules, if tone marks are not written, both Shaanxi and the neighbouring province of Shanxi, to the east of Shaanxi, should be spelled "Shanxi"; the difference is in tone: Shānxī (山西) and Shǎnxī (陕西). To make the difference clear without tonal marks, the spelling "Shaanxi" was contrived (following the romanization system of Yuen Ren Chao) for the province of Shǎnxī, while "Shanxi" is used for the province of Shānxī. Shaanxi is the official spelling on Chinese Government's official web portal. This makes "Shaanxi" the only name of Chinese provinces that has not been romanized according to pinyin rules.