Cairbre Cinnchait or Caitchenn ("cat-head" or "hard head") was, according to medieval Irish legend and historical tradition, a High King of Ireland.
According to the Lebor Gabála Érenn, he succeeded to the throne after the previous incumbent, Conchobar Abradruad, was killed by Crimthann Nia Náir, and ruled for five years.
The Lebor Gabála is unsure of his origins: it says "the learned reckon" he was of either the Luaigne of Tara, the Tuatha Dé Danann, the Catraige of Connacht, the Corcortri (descendants of the former High King Cimbáeth), or a descendant of Ír, son of Míl Espáine.
Keating says Cairbre was either the descendant of a Scandinavian prince who came to Ireland with Labraid Loingsech, or of the Fir Bolg.
He ruled for five years, died of plague, and was succeeded by Elim mac Conrach, who would eventually be overthrown by Fiacha's son Tuathal.