Salamanca (Otomi: Xidoo "Place of Tepetate"), Founded January 1, 1603 as 'Villa de Salamanca' by the Viceroy Gaspar de Zíñiga y Acenedo, fifth Earl of Monterrey, who was originally from Salamanca (Spain). The town was founded in the lands of Bajio, after cattle ranchers and poor farmers, a few Spaniards, and small groups of Otomi Indians who formerly occupied a village named Xidoo, already lived in the area.

In recent years, many refineries have opened, and Salamanca has grown rapidly to become an important site for manufacturing and service industry in the region. Also, the University of Guanajuato has made many scientific contributions to develop agricultural and industrial technologies, giving a boost to the local and regional industries.

The city reported a 2010 census population of 260 mil 759. The fourth-largest city in the state (behind León, Irapuato and Celaya), it is also the largest of four places called "Salamanca" in Mexico.