Overijse is a municipality located in the province of Flemish Brabant within the Flanders region of Belgium. Situated as a suburb of the broader Brussels metropolitan area, the municipality covers a total area of 44.99 km² and had a population of 25,962 as of January 1, 2023.
The municipality includes the town of Overijse proper along with the communities of Eizer, Maleizen, Jezus-Eik, Tombeek, and Terlanen. The area is characterized by extensive woodlands that provide numerous paths for walking and cycling.