The name is used to describe that section of the valley between its source and Huddersfield at the point where the River Holme joins the Colne.
The name can describe the whole valley of the Colne, including the section through Huddersfield its confluence with the River Calder at Cooper Bridge.
Using the more common definition, the Colne Valley includes the towns and villages of Marsden, Slaithwaite, Linthwaite, Milnsbridge, Scapegoat Hill, Longwood and Golcar.
By the end of the Second World War, the importance of the Colne Valley as a centre of textile production had begun to decrease and Huddersfield Narrow Canal was largely abandoned in 1944.
It was created by the merger of Golcar, Linthwaite, Marsden, Scammonden and Slaithwaite urban districts, and had a population of about 20,000.