Ciarán (Irish spelling) or Ciaran (Scottish Gaelic spelling)[2][3] is a traditionally male given name of Irish origin.

The name became common in reference to Ciar, son of Fergus mac Róich,[6] who gave his name to the Ciarraige and County Kerry,[7] and two early Irish saints both counted among the Twelve Apostles of Ireland: Ciarán the Elder and Ciarán the Younger.

It is anglicised in various ways: Ciaran, Kieran, Keiran, Keiron, Keiren, Keerun, Kiran, etc.

According to historian C. Thomas Cairney, the O'Kierans were the chiefly family of the Cíarraige tribe who in turn were from the Dumnonii or Laigin who were the third wave of Celts to settle in Ireland during the first century BC.

[8] The name can also be found in the Irish surname of O'Keiran, meaning "descendant of Ciarán".