San Antonio de la Cal is a town and municipality located in the state of Oaxaca in southeastern Mexico. It is situated within the Centro District of the Valles Centrales region.
The municipality covers an area of 11 km2 and is characterized by its high population density. It ranks as the fifth most densely populated municipality in Oaxaca, following only Oaxaca, San Jacinto Amilpas, Santa Lucía del Camino, and Santa Cruz Amilpas. As of 2005, the municipality had a total population of 15,071.