Oosterzele is a municipality located in the Flemish province of East Flanders, in Belgium. The municipality comprises the towns of Balegem, Gijzenzele, Landskouter, Moortsele, Oosterzele proper and Scheldewindeke. In 2021, Oosterzele had a total population of 13,740. The total area is 43.12 km². Its twin town is Oberkirch in Germany.