 The municipality had a population of 14,515 inhabitants according to the 2005 census.In pre-Hispanic times the area of what is today Tierra Blanca was mostly inhabited by Chichimeca people.Tierra Blanca was founded and granted the title of municipality in 1536 under the order of the first viceroy of New Spain, Antonio de Mendoza, making it one of the oldest in the state of Guanajuato.