The Blackburn Brook is a stream in Sheffield, South Yorkshire, England which flows through the Blackburn Valley along the M1 and Ecclesfield Road and joins the River Don near the Meadowhall shopping centre. Downstream from the A61 road at Chapeltown the Blackburn Brook is defined as a main river by the Environment Agency, which requires new building development to be at least 8m from the bank side as a flood defence measure and to allow access to the watercourse for maintenance.