Tremelo is a municipality located in the Belgian province of Flemish Brabant, in Flanders. The municipality comprises the towns of Baal and Tremelo proper. On January 1 2006 Tremelo had a total population of 13,725. The total area is 21.57 km² which gives a population density of 636 inhabitants per km².
Located in the arrondissement or administrative district of Leuven, the official language is Dutch. Tremelo is most famous for having been the hometown of Father Damien, locally known as Pater Damiaan, a legendary missionary who had tended to the lepers in the Hawaiian Islands.