Ambleteuse (French pronunciation: [ɑ̃blətøz]; West Flemish: Ambeltuwe) is a commune in the Pas-de-Calais department in northern France.

Ambleteuse is one of the candidates for the harbour that Julius Caesar used to set out from for his invasion of Britain in 54 BC, though Boulogne-sur-Mer is the more usually accepted site.

Some scholars claim it has Celtic origins (Ambleat), but that does not exclude the etymology "Hamel Thuys", a name given by the Saxons in the 6th century, as they too used the harbour when they emigrated to Great Britain.

Henry VIII of England had two forts built here in 1546 to maintain a show of power towards the French kings.

Between 1941 and 1943, the German engineers of Organisation Todt installed bunkers for artillery at the fort as part of work on the Atlantic Wall.