The name "Shaanxi" means Land West of the Shanguan Pass. This pass in Henan province, now part of Shanzhou District of Sanmenxia city, was considered to be the place where the Yellow River left the Loess Plateau and entered the North China Plain, although its exposed nature meant that the Hanguguan and Tongguan Passes to its west were more strategically important.

Because the Chinese pronunciation of Shaanxi and its eastern neighbor Shanxi differ only in tone, their spelling differs only by tone marks. The authorities therefore adopted the special official spelling "Shaanxi" for occasions when such marks are omitted.

Shaanxi lies in Northwest China. It covers an area of over 205,000 km2  with about 38 million people. Xi'an—which includes the sites of the former Chinese capitals Fenghao and Chang'an—is the provincial capital. Xianyang, which served as the Qin capital, is located nearby. The other prefecture-level cities into which the province is divided are Ankang, Baoji, Hanzhong, Shangluo, Tongchuan, Weinan, Yan'an and Yulin.

Shaanxi comprises the Wei Valley and much of the surrounding fertile Loess Plateau, stretching from the Qinling Mountains and Southern Shaanxi in the south to the Ordos Desert in the north. Along with areas of adjacent Shanxi province and Henan province, it formed the cradle of Chinese civilization, with its Guanzhong region sheltering the capitals of the Zhou, Qin, Han, Jin, Sui, and Tang dynasties. It does not include the full territory of the Yellow River's Ordos Loop, with the Great Wall of China separating it from the grasslands and deserts of Inner Mongolia.