The River Ely is in South Wales flowing generally southeast, from Tonyrefail to Cardiff.

Tonyrefail is a village and community in the Rhondda Cynon Taf County Borough, Wales. It is situated at the head of the River Ely; 4 miles (6.4 km) northwest of Llantrisant, about 1.5 miles (2.4 km) from Trebanog and about 2 miles (3.2 km) from Williamstown. During the second half of the 19th century, when coal and steel became synonymous with the South Wales Valleys, Tonyrefail evolved from being a rural hamlet to an industrial village. The population at the 2001 census was 11,035.