Chew Valley is within the Saddleworth parish of the Metropolitan Borough of Oldham, in Greater Manchester, England. The valley follows the course of Chew Brook on the western slopes of Black Chew Head to where it joins the River Tame at Greenfield, several miles to the east of Manchester. Part of the higher fringes of the valley towards the peak of Black Chew Head lie across the boundary in Derbyshire.