Sain Alto is a locality in the Mexican state of Zacatecas.

[5] These people were led by a cacique named Saín Alonso.

The earliest Spanish conquistadors to come into contact with the people of Zaín were Ginés Vázquez de Mercado [es] in 1552 and 1553, and Francisco de Ibarra in September 1554.

[5] With the first Zacatecas state constitution of 1825, Saín Alto became the seat of its own municipality.

[5] In the 2020 Mexican Census, Saín Alto recorded a population of 5,295 inhabitants.