Cefn Manmoel is the name given to the broad ridge of high ground between the Sirhowy Valley and Ebbw Vale in the Valleys region of South Wales. It straddles the boundary between the unitary areas of Caerphilly and Blaenau Gwent.
The NNW-SSE aligned ridge reaches a height of 504 metres (1,654 ft) above sea-level at OS grid ref SO 166072. To the south it drops away to a broad saddle southeast of the village of Manmoel, beyond which lies Mynydd Pen-y-fan.
Parts of both its eastern and western flanks are afforested with conifer plantations such as at Coed y Rhyd and at Coed y Llanerch.