Bremenium is an ancient Roman fort (castrum) located at Rochester, Northumberland, England. The fort is part of the defensive system built along the extension of Dere Street, a Roman road running from York to Corbridge and onwards to Melrose. Significantly the fort is a long way north of Hadrian's Wall. It was one of the last forts north of Hadrian's wall to remain occupied until the 270s.

Rochester is a small village and civil parish in north Northumberland, England. It is 5 miles (8 km) north-west of Otterburn on the A68 road between Corbridge and Jedburgh. The village is the site of the Roman fort of Bremenium, built there to protect the important Roman road of Dere Street, which passes through the village.