Masonic Hall, Monmouth

The Masonic Hall is a grade II listed building on Monk Street in Monmouth, Monmouthshire, Wales. It was designed by architect George Vaughan Maddox. The building is believed to mark the site of Monk's Gate, part of the original defences of the town of Monmouth. Before its 1846 conversion to the Masonic Hall, the building served as the Monk Street Theatre.

After more than 150 years of housing the Loyal Monmouth Lodge No. 457, the Masonic Hall sustained fire and smoke damage from suspected arson. The Lodge of Freemasons housed in the building is the oldest surviving Masonic Lodge in Monmouthshire.