Aalter is a municipality located between Bruges and Ghent in the Belgian province of East Flanders. The municipality comprises the towns of Aalter, Bellem, Lotenhulle and Poeke. It is bordered on the north by Knesselare, on the east by Zomergem and Nevele, on the south by Deinze, and on the west by the province of West Flanders. On January 1, 2007, Aalter had a total population of 18,887. The total area is 81.92 km² which gives a population density of 231 inhabitants per km². The mayor is Pieter De Crem.
Effective 1 January 2019, the municipality of Knesselare will be merged into Aalter.