Herk-de-Stad is a municipality located in the Belgian province of Limburg. On January 1, 2006, Herk-de-Stad had a total population of 11,795. The total area is 42.83 km² which gives a population density of 275 inhabitants per km².
Besides the village of Herk-de-Stad itself, the municipality contains the communities of Berbroek, Schulen and Donk. Donk contains two country houses, both of the eighteenth-century, Kasteel Hamont and Kasteel Landwijk, which stands on the site of a castle established in the 12th century.