Santo is on Farm roads 4, 129, and 2201 and the Missouri Pacific Railroad, in southeast Palo Pinto County. It was founded by J. D. T. Bearden between 1850 and 1860 and was originally called Grand Ranch. A nearby makeshift fort provided protection against Indians around 1865. About 1870 the community moved to a site a mile east of the present site on Sunday Creek, and its name was changed to Calgando. Calgando had a mill and a gin. In 1880 the community was moved to its present site and was renamed Cresco. Following a nearly disastrous train wreck caused by confusion of Cresco with Cosco, the town was renamed Sparta. The post office rejected the name Sparta in favor of Santo, derived either from John Santo Statti, an agent for the Texas and Pacific Railway, or from a pioneer, John Adam Santo. In 1920 Santo had a population of 500 and a post office. In 1936 the population remained the same, but the town had fifteen businesses and a bank. By 1940 the population had decreased to 350 and by 1980 to 312, where it remained in 1990. The population grew to 445 in 2000.