Llanllwni is a rural community in north Carmarthenshire between Lampeter (8 miles) and Carmarthen (14 miles). The parish has a population of some 660 souls and covers over 6,600 acres on the west bank of Afon Teifi.

Llan is the most common place-name element in Wales. There is a tendency to accept that llancan only mean ‘church’, but earlier meanings include ‘enclosure’; that meaning still survives inperllan ‘orchard’ and ydlan ‘rickyard’. ‘Sacred ground, cemetery and church’ are all later developments. Llan is also related to the English noun ‘land’.

Although llan is a common place-name element, the place-name per se is more problematic. It occurs for the first time in 1329 in the form Lanthleweni. The form Llanllwni occurs for the first time c.1566 and is the standard form on maps and road signs. The fourteenth century form resembles Lleweni.

Lleweni in Denbighshire belongs to a set of very early place-names that consist of a personal name ‘Llawen’ and a territorial suffix ‘–i’. It means ‘the territory of Llawen’. This evidence has to be considered in any scholarly discussion of the place-name Llanllwni.

The same suffix occurs in another early Carmarthenshire place name Cydweli ‘the territory of Cadwal’.