Coordinates: 51°44′49″N 3°37′01″W / 51.747°N 3.617°W / 51.747; -3.617

Glynneath (Welsh: Glyn-nedd), also spelt Glyn Neath, is a small town, community and electoral ward lying on the River Neath in the county borough of Neath Port Talbot, Wales. It was formerly in the historic county of Glamorgan. Glynneath ward covers only part of the community, with some 840 electors included in the neighbouring ward of Blaengwrach.

Industrialisation reached Glynneath when coal mining started in 1793, and rapidly expanded when the Neath Canal came to the village in 1775. Many features of the old canal still survive to the present time.

There are waterfalls to the north east at Pontneddfechan near the Brecon Beacons and large parts of the rural area are heavily forested.

Glynneath is home to the ruins of Aberpergwm House, once owned by Rhys ap Siancyn; the site now houses St Cadoc's Church (1809). Aberpergwm House became the home of the Williams family, Welsh gentry with a strong tradition of using the Welsh language over English. Their descendants include the last of the Welsh household bards Dafydd Nicolas and folksong collector Maria Jane Williams. The Williams' family motto y ddioddefws y orfu (He who suffers, triumphs) was adopted by Glamorgan County Council. The mansion itself was remodelled in 1876 but is now derelict and little of note remains of the building.