Mont-Saint-Guibert is a Walloon municipality (commune in French) located in the Belgian province of Walloon Brabant. On January 1, 2012, Mont-Saint-Guibert had a total population of 7000. The total area is 18.63 km2 (7.19 sq mi) which gives a population density of 344 inhabitants per square kilometre (890/sq mi).
In addition to Mont-Saint-Guibert itself, the municipality includes the villages of Corbais and Hévillers.