The name of the town in the Irish language is Daingean Uí Chúis, which is widely accepted to mean The Fortress of the Husseys. The Husseys were a Norman family who arrived in Dingle shortly after the Norman invasion of 1169.
There is however, a second interpretation of the meaning Daingean Uí Chúis. The Annals of the Four Masters which were compiled by four Franciscan friars between 1632 and 1636 refer to a pre-Norman chieftain named O Cuis who ruled the area prior to the Norman invasion and had his principle fortress here, hence the name Daingean Uí Chúis.
Whatever the true meaning of the name is, earliest records show the two names of Dingle and Daingean Uí Chúis appearing side by side since the mid 13th century.