Cowhill (archaically Cow Hill) is a locality of Chadderton, in the Metropolitan Borough of Oldham, Greater Manchester, England. It is located 0.5 miles (0.80 km) southeast of Chadderton town centre close to its eastern boundary with Oldham and is contiguous with the Block Lane, Stock Brook, Butler Green and Nimble Nook areas of the town and with Freehold and Westwood in Oldham. Cow Hill sub post office, located at 299 Denton Lane, was the last institution to bear the locality's name. It closed as part of the Post Office's restructuring of services in 2008–09.