Letterston (Welsh: Treletert) is a parish and community in north Pembrokeshire, Wales. It lies on the A40, with Haverfordwest 10 miles to the south and Fishguard 7 miles to the north. At the 2011 census the community had a population of 1,245, up from 998 in 2001, and around 42 per cent of residents could speak Welsh.
Letterston takes its name from Lettard, a Norman knight who settled here in the early 12th century. Over the centuries the name appeared in many forms – in 1230 it was recorded as Ecclesia de Villa Letardi, and later as Lettard, Leeston and Littardston – before the modern spelling became standard. Lettard is remembered as a harsh lord and persecutor of the clergy, and was killed in 1137 by a Welshman, Anarawd ap Gruffydd, marking the end of strong Norman influence in the area. The Lettard family later gave the church living, together with the chapel of Llanfair, to the Knights of St John of Jerusalem at Slebech.
A farmstead to the west of the village called Heneglwys (“old church”) may stand on the site of an early medieval church that preceded the present one. The parish church of St Giles stands within the planted Anglo-Norman settlement, thought to date from before 1120; its dedication is believed to be a corruption of the Celtic dedication to St Sulien. The current building was first built in 1844–45, completely remodelled in 1881, and extended to the west in 1926. The older part of the village lies west of the A40 along St Davids Road, where the church stands.
In the early 1870s the parish covered some 2,216 acres with a population of 511 living in 120 houses, and Heathfield Lodge was noted as the principal residence.
The village grew with the coming of the railway. The North Pembrokeshire and Fishguard Railway opened to Letterston for goods in March 1895 and for passengers in April that year, but financial difficulties led the Great Western Railway to buy the company in 1898. The western part of the village flourished after the station opened, giving Station Road its name. In 1906 the GWR opened a more direct double-track line to Fishguard Harbour, the Clarbeston Road and Letterston Railway, joining the older line at Letterston Junction. Letterston station closed to passengers in October 1937 and closed completely in 1965. A second stop, Mathry Road Halt, about a mile north-west of the village, served the main line from 1923 to 1964; that line remains open today for services to Fishguard.
During the Second World War a small prisoner of war camp for Luftwaffe aircrew operated at Bwlch y Defaid on the west of the village, and parts of it still survive on private land. The village hall was officially opened in November 1940 on land gifted by local landowner Captain Mathias of Llangwarren; originally simply the village hall, it later became known as the Memorial Hall. The village war memorial, a polished grey granite pillar set into St Giles churchyard, records the names of those who fell in both World Wars, alongside a memorial slab to the fallen of the parishes of Llanfair Nant-y-gof and Llanstinan.