San Andrés Huayapam is a town and municipality located in the state of Oaxaca in south-western Mexico. It is situated within the Valles Centrales region and specifically falls under the jurisdiction of the Centro District.
The municipality covers a total area of 14.03 km2 and forms part of the IV Federal Electoral District of Oaxaca. Geographically, the municipality includes a portion of the Benito Juárez National Park. As of 2005, the local population was recorded at 4,508 residents.