Monmouth Castle is a castle close to the centre of the town of Monmouth, the county town of Monmouthshire, on a hill above the River Monnow in south-east Wales.

Monmouth is a market town and community in Monmouthshire, Wales, situated on where the River Monnow joins the River Wye, two miles from the Wales–England border. The population in the 2011 census was 10,508, rising from 8,877 in 2001. Monmouth was the county town of historic Monmouthshire, although Abergavenny is the largest settlement and Monmouthshire County Council has its main offices at Rhadyr, just outside Usk. Monmouth is in the Monmouth UK Parliament and Senedd constituencies.