The Avranchin is an area in Normandy, France, corresponding to the territory of the Abrincates, tribe of Celts who also gave their name to the city of Avranches, main town of the Avranchin.
In 867, by the Treaty of Compiègne, Charles the Bald gave the Avranchin to Salaün, King of Britanny. Then in 933 it was reunited to the Duchy of Normandy by William I, Duke of Normandy.