Dilham's name is of Anglo-Saxon origin, and derives from the Old English for a farmstead or homestead with an abundance of dill.

In 1086, the village was divided between the estates of Alan of Brittany, Robert Malet, Roger Bigod and St Benet's Abbey.

[2] Nearby Dilham Castle was built in the fifteenth century as a fortified manor house for Sir Henry Inglose; all that remains of the castle is the Grade II listed tower currently attached to Hall Farm.

[3][4] During the Second World War, the North Walsham and Dilham Canal was designated as a line of defence against a possible German invasion which meant that bunkers, barbed wire and mortar-emplacements were built in the parish.

The village's national constituency is North Norfolk, which has been represented by the Liberal Democrat Steff Aquarone MP since 2024.