Kelly \k(el)-ly\ as a girl's name (also used as boy's name Kelly), is pronounced KEL-ee. It is of Irish and Gaelic origin, and the meaning of Kelly is "descendant of Ceallach". Transferred use of the surname. Originally an anglicized form of the ancient Irish Gaelic name Ceallach, possibly meaning "bright-headed", "strife", or "church, monastery". Actresses Kelly McGillis, Kelly Preston, Kelly Ripa.