Llanvelig 1254, Llanvyllyn c.1291, Llanvetlin 1293, Lanvethling 1309, Llanvilling 1504, Llanfylling 16g. gynnar, Ll.fyllinn c. 1566, Ll.mylling ymhowys 1575, Llanvulling 1583, Llanvelling 1588, Llanvylling 1702.O bosib hefyd Llanwyllyn 1383. Llanfyllin - "The Church of St Myllin". Little is known about Myllin, other than the fact that he was an Irish Saint originally named 'Moling' (or 'Melingus' according to Gerallt Gymro). This spelling would help explain why the town is sometimes spelled 'Llanfylling'. Dafydd ap Gwilyn notes these few words by St Myllin: O danyn, eiddyn oddef, Meillion awr, Myn Myllin Nef. It seems that an early legend claimed that the name 'Myllin' stemmed from 'mewn llyn' ('in a lake'), as the Saint was always in the water baptising infants.