(Patrick John) Pat McCartan (born 5 May 1953) is an Irish Circuit Court judge and a former politician. A native of Wexford he was first elected to Dáil Éireann at the 1987 general election as a Workers Party Teachta Dála (TD) for the Dublin North East constituency. He was re-elected at the 1989 general election.
In 1992 he joined with Proinsias De Rossa and five other Workers Party deputies in resigning from the Workers Party and in the creation of a new party, New Agenda which subsequently became Democratic Left. He stood as a Democratic Left candidate at the 1992 general election but lost his seat. After the collapse of the 1992–94 Fianna Fáil / Labour Party coalition government Democratic Left joined in a new coalition with Fine Gael and the Labour Party. This government subsequently appointed McCartan to the bench as a Circuit Court judge.