Caerleon, Monmouthshire, is a suburb of Newport chiefly known as the site of a Roman legionary fortress. It is located on the river Usk. The name Caerleon ultimately means "fortress of the legion;" the Romans themselves called it Isca Silurum, "Usk of the Silures," after the Silures, the Celtic tribe that dwelt there.

Substantial remains can still be seen, including the military amphitheatre, one of the most impressive in Britain, and the bath house, with a modern museum in situ above it. Both sites are administered by Cadw. There is a separate museum, part of the National Museums and Galleries of Wales complex, which exhibits finds from excavations throughout the village.