Caoimhghín Ó Caoláin (['ki?v?i?n? o? 'ki?l?a?n?]; born 18 September 1953) is an Irish Sinn Féin politician who has been a Teachta Dála (TD) for the Cavan–Monaghan constituency since the 1997 general election.
He was appointed Chair of the Committee on Justice and Equality in April 2016.
He served as Leader of Sinn Féin in Dáil Éireann from 1997 to 2011.