It was created at the 1918 general election as a county division of Derbyshire, comprising the area in the centre of the county and surrounding Derby, and named after the market town of Belper although this was in the north of the constituency.

The area had an ever-expanding population after 1945 as prosperous suburbs of Derby were built outside the city boundaries.

Lord George-Brown, who represented the seat at the time, wrote in 1971 after his defeat in the 1970 general election that "The electorate had increased by over 10,000 since 1966, mainly from the growth of middle-class housing estates, so that most of the new electors could be expected to vote Tory.

When created in 1918, the constituency consisted of the Urban Districts of Alfreton, Belper and Heage, together with the Rural District of Belper and part of the Rural District of Repton (the civil parishes of Ash, Bearwardcote, Bretby, Burnaston, Dalbury Lees, Egginton, Etwall, Findern, Foremark, Ingleby, Mickleover, Newton Solney, Radbourne, Repton, Trusley, Twyford and Stenson, and Willington).

In 1974 the boundaries were realigned with those for local government which had changed to transfer some electors to Derby; the constituency consisted of the urban districts of Belper and Swadlincote, and the rural districts of Repton and Belper except the civil parish of Shipley.