Leerdam (Dutch: [leːrˈdɑm]; population: 20,563 in 2014) is a city and municipality in the western Netherlands, in the province of South Holland.

The municipality covers an area of 34.42 km (13.29 sq mi) of which 0.63 km (0.24 sq mi) is water. It comprises the town of Leerdam, the rural villages Kedichem, Schoonrewoerd and Oosterwijk. The south border of the town is formed by the river Linge. Leerdam is the most eastern town of the province of South Holland and is situated almost exactly in the middle of the three highways A2, A15 and A27.