John Joseph McCartin (born 24 April 1939) is a former Irish Fine Gael politician who served as a Member of the European Parliament (MEP) for the Connacht–Ulster constituency from 1979 to 2004. He served as a Teachta Dála (TD) for the Sligo–Leitrim constituency from 1981 to 1982 and 1982 to 1987. He also served as a Senator for the Agricultural Panel from 1973 to 1981.