The Colne Valley is a steep sided valley on the east flank of the Pennine Hills in the English county of West Yorkshire. It takes its name from the River Colne which rises above the town of Marsden and flows eastward along the floor of the valley.
The name is generally used to describe that section of the valley of the River Colne that lies between its source and the large town of Huddersfield, which lies at the point where the River Holme joins the River Colne. Less often, the name is used to describe the whole valley of the Colne, including the section through Huddersfield and on to the confluence of the Colne with the River Calder at Cooper Bridge. Using the more common definition, the Colne Valley includes the towns and villages of Marsden, Slaithwaite, Linthwaite and Golcar.
The Colne Valley played a significant role in the development of the Industrial Revolution. Most of the population had been weavers for generations, so when water-powered textile mills were built on the many streams and small rivers in the area, the area was well set to become a major producer of textiles. The River Colne and the Huddersfield Narrow Canal provided early transport links which were soon added to by road and railway links to Huddersfield and Leeds to the east and Manchester and Liverpool to the west.