Monmouth, town, historic and present county of Monmouthshire (Sir Fynwy), southeastern Wales. It is situated at the confluence of the Rivers Wye and Monnow on the English border.

The town of Monmouth, granted its first royal charter in 1256, became important as the market for a rich agricultural region. Historical features include remains of an 11th-century Benedictine priory, a 13th-century gateway on Monnow Bridge, a boys’ school founded in 1614, the 17th-century Wye Bridge, and the Shire Hall (1724). On nearby Kymin Hill the Naval Temple was built (1800) to honor 18th-century admirals. Lord Nelson had many associations with Monmouth, and the town’s Nelson Museum houses a fine collection of his relics. Monmouth is the historic county town (seat) of Monmouthshire. Pop. (2001) 8,877; (2011) 10,508.