The River Yarrow is a river in Lancashire in the north west of England. It is a tributary of the River Douglas.

It rises on Rivington Moor near Upper Rivington Reservoir, passes under the M61 motorway and the Leeds and Liverpool Canal. South of Chorley it is joined by the Black Brook and broadens out; it passes through Yarrow Valley Park, then flows north, south of Euxton, north of Eccleston, and through Croston. It is joined by the River Lostock and joins the River Douglas east of Sollom and south of Tarleton.