Cwmfelinfach is nestled in the heart of Caerphilly County, South Wales. It is bordered by Ynysddu to the north, Trethomas to the south, Llanbradach to the west and Crosskeys to the east, with nearby villages and towns including Risca, Blackwood, Newbridge, Abercarn and Caerphilly.

The Sirhowy river passes through Cwmfelinfach before meeting the Ebbw river at Crosskeys. There are many walks and trails criss-crossing the hills and valleys and the Sirhowy Valley Walk and the Raven Walk meander past the town.

Cwmfelinfach made its name in the coal mining industry of the late 1800s. Nine Mile Point Colliery opened in 1905 and its deepest shaft was 1,176 feet deep. Unlike many of its neighbouring collieries, Nine Mile Point saw few disasters and tragedy. In 1935, 164 men took part in South Wales' first sit-in protest over the use of scab labour. The colliery was closed in 1964 and demolished, after it was announced that it was too uneconomical to run.

The disused Babell Chapel at Cwmfelinfach includes the grave of the well-known 19th century Welsh poet, Islwyn.