The Black Dub is a stream in Cumbria, United Kingdom. It rises to the west of the village of Langrigg, in the civil parish of Bromfield, where it is known as Dub Stangs, and flows west past Scroggs Wood and the village of Westnewton. As it passes near the hamlets of New Cowper and Edderside it forms the southern boundary of the civil parish of Holme St. Cuthbert, and the northern boundary of the civil parish of Allonby, before entering the Solway Firth at Dubmill, at the northern end of Allonby Bay. It is seven miles in length.