San Ildefonso Ixtahuacán is a municipality located in the department of Huehuetenango, Guatemala. Situated at an elevation of 1,580 metres above sea level, the municipality covers a total area of 135 km2 (52 sq mi) and has a population of 44,424.
The town of Ixtahuacán serves as the municipal seat. The region hosts an annual festival held from January 20 to January 25.