Afon Cych (standard Welsh orthography: Afon Cuch) is a small river tributary to the River Teifi in south-west Wales. Its "official" source (although not its highest headwater) is at Blaencych (51°57′53″N4°29′28″W). It flows north-westwards through a deep, wooded, secluded valley, and joins the River Teifi at Abercych (52°2′36″N4°33′34″W). Its total length is 13 km. It receives numerous small tributaries: the Sylgen, Barddi, Mamog, Dwrog and Lŵyd on the east side, and the Pedran, Cneifa and Dulas on the west side.