The Cotentin Peninsula (French pronunciation: [kotɑ̃tɛ̃]), also known as the Cherbourg Peninsula, is a peninsula in Normandy that forms part of the northwest coast of France. It extends north-westward into the English Channel, towards Great Britain. To its west lie the Channel Islands and to the southwest lies the Brittany Peninsula.
The peninsula lies wholly within the department of Manche, in the region of Normandy.
It is part of the Armorican Massif (with the exception of the Plain lying in the Paris Basin) and lies between the estuary of the Vire river and Mont Saint-Michel Bay. It is divided into three areas: the headland of La Hague, the Cotentin Pass (the Plain), and the valley of the Saire River (Val de Saire). It forms the bulk of the department of Manche. Its southern part, known as "le Marais" (the Marshlands), crosses from east to west just to the north of Carentan and Lessay and marks a natural border with the rest of Manche.
The largest town in the peninsula is Cherbourg on the north coast, a major cross-channel port. Other towns of note: Valognes, Barfleur, Bricquebec, Barneville-Carteret, Beaumont Hague, Les Pieux, La Haye du Puits, Montebourg.