Clydach may refer to any of various settlements and rivers in South Wales:
- Clydach, Monmouthshire (village)
- Clydach, Swansea (village)
- Clydach Gorge, (Welsh Cwm Clydach) Monmouthshire
- River Clydach, Monmouthshire, (Welsh Afon Clydach)
- Lower Clydach River, Swansea Valley
- Upper Clydach River, Swansea Valley
- Clydach Vale, (Rhondda Cynon Taff)