Mac Eoin, MacEoin or McEoin is an Irish surname. Notable people with the surname include:
- Denis MacEoin (born 1949), Irish editor
- Gearóid Mac Eoin (born 1929), Irish academic
- Seán Mac Eoin (1893–1973), Irish politician
- Tomás Mac Eoin (born 1937), Irish singer
- Owen MacEoin Dubh MacAlister (?–1571), Chief of Clan MacAlister
- Athairne Mac Eoghain (1200–1600), Irish poet