Aa en Hunze () is a municipality in the northeastern Netherlands. The municipality has 26,089 inhabitants. The town hall is located in Gieten. The municipality of Aa en Hunze was created on 1 January 1998 by merging the municipalities of Rolde, Gasselte, Gieten, and Anloo.
The names 'Aa' (more precisely the 'Drentsche Aa') and 'Hunze' refer to two small rivers through the municipality. The municipality consists of two distinct parts, each with a different history. The two parts are separated by the Hondsrug, which itself belongs to the western part. This sandy area is among the oldest inhabited regions in the Netherlands. The eastern part of the municipality has a much shorter history of habitation.
There is no railway station in the municipality. The nearest station is Assen railway station.