The Darini (Δαρῖνοι) (manuscript variant: Darnii [Δάρνιοι]) were a people of ancient Ireland mentioned in Ptolemy's 2nd century Geography as living in south Antrim and north Down. Their name implies descent from an ancestor called Dáire (*Dārios), as claimed by several historical peoples, including the Dál Riata and Dál Fiatach (Ulaidh) in the same area of eastern Ulster as well the Érainn (Iverni) of Munster. An early name for Dundrum, County Down, is recorded as Dún Droma Dáirine, and the name Dáirine was applied to the Érainn dynasty.
The cognate Dari(o) ("agitation, tumult, rage") is a form widely attested in the Gaulish language, especially in personal names, and exists in the Welsh language as cynddaredd ("rage"). Thus the Darini may have been considered a people "of great violence" and descendants of a so called "red god" Over time, however, the Irish personal name Dáire would develop the meaning of "rutty" or "violent apparently following a meaning of "bestial rage".
It is worth noting that Dáirine can sometimes refer to the so-called Érainn dynasties altogether and not only to the Corcu Loídge and their corelatives in Munster.
Cú Roí mac Dáire is a king from Munster who appears frequently in the Ulster Cycle possibly reflecting memories of the prehistoric Darini when their power was great in Ireland. The Dál Fiatach of Ulster later claimed descent from his semi-divine clan, the Clanna Dedad, further associating the two provinces—although seemingly in contradiction to their descent from the Ulaid or Voluntii proper, until it is remembered that the Darini and Voluntii lived adjacent to one another in Ptolemy's Ireland and were no doubt ancient kin. Cú Roí's father was Dáire mac Dedad. The Clanna Dedad take their name from his grandfather, Deda mac Sin.