Llantrinew 1254, Landrimeaw c.1291, Llandrunion in Dendour 1309, Landrunyawe 1361, Llandrunyo 1385, Llandrineawe 1399, Llandrunio 1425, (bridge of) Landrvine 1478, llann Drinio late 15th C., Llandrynyo 1535, ll.drinio c.1566, Llandrynio 1567, Llandrinio 1568, 1836

'Church of (St) Trunio'. (or ‘Trinio’) reputedly a grandson of Emyr Llydaw (Budic II of Brittany), a 'Dark Age' ancestor of a number of saints recorded in medieval manuscripts of Bonedd y Saint, 'Lineage of the Saints'.
Llandrinio is recorded in 1526 as a place of pilgrimage.