Subprefectures (sous-préfectures) are the administrative towns of arrondissements in France that do not contain the prefecture for its department. Subprefecture is also the name given to the building which houses the administrative headquarters for the arrondissement.
The civil servant in charge of a subprefecture is the subprefect, assisted by a general secretary. Between May 1982 and February 1988, subprefects were known instead by the title "commissaire adjoint de la République".
Where the administration of an arrondissement is carried out from a prefecture, the general secretary to the prefect carries out duties equivalent to those of the subprefect.
Paris is unique in that it has no subprefecture made up of only a single prefecture. The municipal arrondissements of Paris (as well as of Lyon and Marseille) are divisions of the city (or commune) rather than the prefecture, and so are not arrondissements in the same sense.