McCartan is a surname of Irish origins. Derived from Mac Artáin, which denotes the son of Artán, the surname was taken by chiefs of Kinelarty in County Down. The surname was thought to have lost its prefix to become Carton, Cartin, Carten and Cartan. but these names are now recognised as derivatives of Uí Mhic Cairthinn.
The McCartans belong to the Uí Echach Cobo branch of the Dál nAraidi dynasty of the Cruthin, and thus are kin to the Magennis family, Lords of Iveagh. The McCartans were briefly Lords of Iveagh. French President Charles de Gaulle is descended from the clan through his great-grandmother Angélique McCartan.
- Daniel McCartan, Gaelic footballer, brother of James McCartan, Junior
- Edward McCartan (1879-1947), American sculptor
- Jack McCartan (born 1935), American hockey goaltender
- James McCartan, Senior, Gaelic footballer (1950s-1960s) and manager (1980s)
- James McCartan, Junior, Gaelic footballer (1990-2000) and manager, son of the above
- Michael McCartan (1851–1902), Irish nationalist politician, MP for South Down 1886–1902
- Pat McCartan (born 1953), Irish judge and former politician
- Patrick McCartan (1878-1963), Irish republican and politician
- Shay McCartan (born 1994), Northern Irish footballer
- Arthur Guinness, believed to have McCartan origins 
- Guinness family, the prominent Anglo-Irish family
- Earl of Iveagh
- Neafsey, E. All New Surnames of Ireland (Dublin, 2002) ISBN 0-940134-97-7