Chepstow (Welsh language: Cas-gwent) is a border town straddling the Monmouthshire/Gloucestershire border, situated at the confluence of the River Wye and River Severn. It is famous for its castle and racecourse , which hosts the Welsh Grand National .

In the middle ages Chepstow was the largest port in Wales, this distinction was lost to the cities of Cardiff, Newport and Swansea during the industrial revolution, as they were more suitable for handling the export of coal and steel from the Glamorganshire and Monmouthshire valleys. The medieval town wall (locally known as the port wall) still stands, and particularly good sections can be seen at the castle dell cark park, and near the A48 road.

Chepstow is located near the old Severn Bridge which has the second longest span of any bridge in the UK. The town has a recently built PFI funded community hospital and two new housing estates.

Chepstow is twinned with Cormelles , France.