The "arrondissement" of Saint-Dizier is the most northern of the "arrondissements" of the Haute-Marne department. It is bordered to the north and east by the Meuse department, to the southeast by the Vosges department, to the south by the Arrondissement of Chaumont "arrondissement", to the west by the Aube department and to the northwest by the Marne department.