Erewash is a local government district with borough status in Derbyshire, England. The borough is named after the River Erewash. The council has offices in both the borough's towns of Ilkeston and Long Eaton. The borough also includes several villages and surrounding rural areas. Some of the built-up areas in the east of the borough form part of the Nottingham Urban Area.

The River Erewash is a river in England, a tributary of the River Trent that flows roughly southwards through Derbyshire, close to its eastern border with Nottinghamshire.