Fort Beauséjour is a Canadian national historic site in Aulac, New Brunswick .

The fort was built in 1751 in Acadia in response to the construction of Fort Lawrence by the British, across the Missiquash river, which divided British-held Nova Scotia from Acadia.

In June 1755, the fort fell to the British, led by Lt. Col. Robert Monckton , after which it was used during the expulsion of the Acadians from the region.

The British renamed Fort Beauséjour Fort Cumberland, and repelled attacks from local rebel forces and Americans led by Jonathan Eddy in 1776.