Santiago Teyahualco is a town located in the municipality of Tultepec within the State of Mexico. It serves as the second-largest town in the municipality.
According to the 2005 Mexican census, the town had a population of 47,547 inhabitants, consisting of 23,357 men and 24,190 women. The community is primarily characterized by its traditional feast dedicated to the town's patron saint, which features local food, castles, bulls, and fireworks.