The Irish surname Kellie is of patronymic origin deriving from the Gaelic name O'Ceallaigh, meaning "strife" or "contention". The main (O')Kelly clan belonged to Ui Maine (mid Galway and South Roscommon), and the reigning chieftain, O'Ceallaigh (circa 1351), was a renowned patron of the arts. O'Kelly of Gallagh, whose claim to the designation chief of the name is officially recognized is entitled to be called the O'Kelly. Today the name Kellie is found throughout Ireland and is very popular in England, Australia and the US. A notable bearer of the name is Ned Kelly the Australian outlaw.