Leersum is a town in the municipality of Utrechtse Heuvelrug in the Dutch province of Utrecht.

The built-up area of the town was 1.44 km2; it contained 2465 residences.

In June 2021, Leersum was hit by a downburst.

Many cars and homes were heavily damaged by falling trees.

Staatsbosbeheer, the Dutch state forest administration, estimates that damaged sections of forest will not be reopened to the general public before the end of the year 2021.