Blackburnshire was a former district of England around the town of Blackburn. It was divided into the four forests of Accrington, Pendle, Trawden and Rossendale.

The shire probably originated as a county of the Kingdom of Northumbria, but was much fought over, and by the time of the Domesday Book it was considered a hundred of Cheshire. The separateness of the district was reinforced when it became a royal bailiwick in 1122. In 1182, it became part of the newly-created county of Lancashire. Over time, the term fell out of use, but it remained a hundred until the abandonment of that system in the early nineteenth century.

Hundreds of England | History of Lancashire