The episcopal see covers the historic county of Monmouthshire with the bishop's seat located at Newport Cathedral (commonly known as St Woolos' Cathedral) in the city of Newport.

The former Church of St Woolos, which had existed in Newport since the sixth or seventh century AD, was originally the temporary seat of the Bishop when the Diocese of Monmouth was created in 1921.

St Woolos was eventually raised to Cathedral status in 1949.

Her immediate predecessors were Richard Pain, previously Archdeacon of Monmouth, and Dominic Walker OGS, previously area Bishop of Reading in the Church of England.

The Diocese of Monmouth has also produced a number of Archbishops of Wales, most notably Rowan Williams, who was subsequently appointed Archbishop of Canterbury in 2002 - believed to be the first Welsh-born bishop to hold that post since the English Reformation in the 16th century.