La Jacetania (Aragonese: A Chacetania; French: Jacétanie) is a comarca in northern Aragon, Spain. It is located in the northwestern corner of the Huesca and Zaragoza provinces. The administrative capital is Jaca, which with a population of 13,374 is the largest town in the comarca. The area is famous for its ski resorts.
Jacetania is bordered by France to the north and Navarre to the west. Most of its territory is mountainous, with the ranges of the Pyrenees and Pre-Pyrenees covering most of its area. The name of the comarca originates in the ancient Iberian tribe of the Iacetani (Latin: Iaccetani).