The Geological Survey of Belgium (GSB, French: Service géologique de Belgique) is a Belgian federal research institute for Belgian geology. It is a department of the Royal Belgian Institute of Natural Sciences. The institute is as a resource centre and project partner which produces maps, books and databases of Belgian geology. The GSB is a member of the European Geological Surveys network.
The institute was founded in 1896 and includes a Documentation Center for Earth Sciences on geological and hydrogeological data and a Research and Development department.