Santiago Tilantongo is a town and municipality in Oaxaca in south-western Mexico.

It is part of the Nochixtlán District in the southeast of the Mixteca Region.

As of 2005, Santiago Tilantongo had a total population of 3,348 living in 827 residences.

Almost half speak an indigenous language, and all but about 200 are Roman Catholic.

The municipality has a pre-school, an elementary school and a telesecundaria, as well as a rural medical clinic, a tianguis market, and a Dominican church.