Cwmafan, also known as Cwmavon, is a large village and community in the Afan valley in Wales, lying within Neath Port Talbot County Borough. It had a population of 5,603 in 2001, increasing slightly to 5,615 at the 2011 Census. Cwmafan is known for having a high percentage of Welsh speakers. In many ways it is a suburb of the nearby town of Port Talbot which is less than 2 miles (3 km) to the south. The literal translation of Cwmafan from Welsh to English is complex, Cwm means valley with Afan as the name of the river flowing through, hence the village residing within the Afan Valley. It could be a version of Afon which means river, so literally the "River Valley", this is common in Wales and the UK with many rivers being called Afon or Avon. There is also a Saint Afan, which it is possible the river was named after. There have been other suggestions but none accepted locally.

The River Afan is a river in Wales whose valley formed the territory of the medieval Lords of Afan. The Afan Valley encompasses the upper reaches of the river. The valley is traversed by the A4107 road. Settlements in the area include Cwmafan, Pontrhydyfen and Cymmer. The town of Aberavon, whose name in Welsh Aberafan means 'mouth of the Afan', grew up on the banks of the river and was later subsumed by the town of Port Talbot.