Teoloyucan is a municipality situated in the northeastern part of the State of Mexico, Mexico. It serves as part of the Greater Mexico City urban area and is located approximately 45 km (28 mi) north of the Federal District.
The city of Teoloyucan serves as both the municipal seat and the second largest city within the municipality. The name of the area originates from the Nahuatl language, meaning "place of glass" or "place of crystal rock." During the colonial period, various historical names for the location were recorded, including Teohuilloyocan, Teohuilloyucan, Theoloyucan, Teoloyucan Coaquileque, and Tehuilloyocan.