Cadoxton (/ˈkædəkstən/; Welsh: Tregatwg) is a district of Barry in the Vale of Glamorgan, Wales.

Over the years remains have been found that suggest Cadoxton, (under a different name), was once a Roman settlement.

The name 'Cadoxton' derives from the 6th century Saint, Cadoc, and the Old English word "ton" meaning settlement; the ancient parish church of St Cadoc (called locally "the Old Village Church") still stands on Cowbridge Street — As of 2022[update], it is part of the Church in Wales' Barry Ministry Area.

[2] The ruins of a chapel dedicated to Cadoc's disciple, Saint Baruc, can still be seen in Friars Road on Barry Island.

The village grew rapidly in the 19th and 20th centuries after the construction of Barry Docks in 1889.