Leersum (52°1′N5°26′E / 52.017°N 5.433°E / 52.017; 5.433) is a town in the Dutch province of Utrecht. It is a part of the municipality of Utrechtse Heuvelrug, and lies about 9km west of Veenendaal.
In 2001, the town of Leersum had 6013 inhabitants. The built-up area of the town was 1.44km², and contained 2465 residences.