St Athan (Welsh: Sain Tathan) is a village and community in the Vale of Glamorgan in South Wales.

[3] Legend holds that Tathan was an Irish monk who was in a boat which ran aground at Portskewett, after being blown across the Bristol Channel, around 540 AD.

However, somewhat confusingly, a Tathan the Younger is said to be buried at St Athan Parish Church, although the exact location of the grave is unknown.

[5] Others say the village obtained its name from Tathana, granddaughter of Meuric ap Tewdric of Trebeferad (Boverton), who lived a humble life as a nun in a mud hut on the River Thaw, near the Old Mill; she was associated with the monastic school of nearby Llantwit Major, and was buried at the church.

[7] The early history of the parish of Eglwys Brewis records that it was situated in the manor of St Athan and was held by the same lordship as that of Castleton.

[7] Roman coins have been discovered in the vicinity including a find in 1798 in a field between St Athan and Eglwys Brewis.

ATHAN, ST., in the Cwmwd of Maenor Glynn Ogwr, Cantref of Cron Nedd (now called the Hundred of Ogmore), County of GLAMORGAN, South Wales: a Rectory, valued in the King's Books at £15..9..7: Patron, Robert Jones, Esq.

[13] On 23 February 2016 Aston Martin announced that their new factory to build its DBX crossover model would be located on the airfield at St Athan.

St Athan is the name of the electoral ward, coterminous with the community, which elects one county councillor to the Vale of Glamorgan Council.

The following landmarks are listed buildings of St Athan and its sub-manors:[20][21] The main entrance to the Grade I listed Parish Church of St Athan (partially restored 1888–90)[23] lies on the south porch, which contains the remains of a sundial and displays the Berkerolles coat of arms, dated to the 13th or 14th century.

[6] The large rounded font which stands on a square three-foot high base is made of Sutton stone retrieved from the Ogmore River and appears to date to the earlier Norman church.

[21] A number of dwellings in the village hold listed status in recognition of their special architectural or historic interest.

It is the last cottage in the area with a thatched roof, and retains period features such as heavy oak beams and an old iron bread-oven.

The Croft is a cottage which dates to the late 19th or early 20th century and is noted for its rounded-head door opening and symmetrical facade.

[27] East Orchard, a castle within the village, was built in 1691 by Roger Berkerolles; curiously, in 1843, a wild fig tree grew out of the cement of the chapel walls.

Its unusual architectural features include its five inline chimneys, a "Tudor arched doorway, broad chamfered beams and gabled porch".

The memorial, built from Portland stone ashlar, is a square pillar raised on three steps with a dentilated cornice, capped by a ball.

[21] The Church of St Athan contains monuments of the Berkerolles family with recumbent figures of a knight and his lady.

The library is currently moving from County Council[31] control to a Community Charity[32] after a consultation took place between October and December 2014.

[34] The village has a post office,[35] a Londis,[36] a Laser and tattoo removal service,[37] a pharmacy,[38] an Esso petrol station [39] and an Aston Martin Lagonda auto plant.