Aridaia is a town and former municipality located in the northwest corner of the Pella regional unit in Greece. Geographically, it borders the southern part of North Macedonia to its west and the northeast corner of the Florina regional unit to its north. The town served as the capital of the former Almopia eparchy.
Following the 2011 local government reform, Aridaia became a municipal unit within the larger Almopia municipality. The municipal unit covers a land area of 562.910 km² and is divided into 17 communities. While the population of Aridaia proper is 7,118, the total population for the entire municipal unit is 18,864.