Cairbre Lifechair ("lover of the Liffey"), son of Cormac mac Airt, was, according to medieval Irish legend and historical tradition, a High King of Ireland.
During his reign, his sons Fiacha Sraibhtine and Eochaid Doimlen killed Óengus Gaíbúaibthech.
However, the fianna demand a tribute of twenty gold bars, which they claimed was customarily paid on such occasions.
Cairbre decides the fianna have become too powerful, and raises a huge army from Ulster, Connacht and Leinster against them.
The chronology of Geoffrey Keating's Foras Feasa ar Éirinn dates his reign to 245–272, the Annals of the Four Masters to 267–284.