Vestfold is a former counties in Norway. It bordered Buskerud and Telemark. The county administration was in the city of Tønsberg. Vestfold was west of the Oslo Fjord. The river Numedalslågen runs through the area. Many islands are at the coast. Vestfold is mostly lowland areas. It is among the best agricultural areas of Norway.
Vestfold used to be a headquarters for whaling fleets. The economy of the coastal towns of Vestfold now is centered around fishing and shipbuilding. Some lumbering is done away from the coast. The district also has some of the best farmland in Norway.
Vestfold County has a total of 14 municipalities: