what nationality is the last name kelly
KELLY Surname Meaning & Origin: The Kelly surname, along with common variants Kelley and Kellie, has a number of possible origins.Most commonly it loosely means descendant of war, from the ancient Irish name O'Ceallaigh..The Gaelic prefix O indicates male descendant of, plus the personal byname Ceallach meaning strife or contention.The name may also mean bright headed.. Kelly is the 2nd most common surname in Ireland and the 69th most popular surname in the United States.he Gaelic prefix O indicates male descendant of, plus the personal byname Ceallach meaning strife or contention. The name may also mean bright headed.. Kelly is the 2nd most common surname in Ireland and the 69th most popular surname in the United States.