Kelly is the anglicized Irish surname Ó Ceallaigh — from the Old Irish cellach ("warrior, strife" or possibly "frequenting churches"). Originally a masculine surname; shifted majority-feminine in the United States in the 1950s after Grace Kelly's films. A top-15 US baby name from 1968 to 1979, peaking at #11 in 1977. Kelly Clarkson (born 1982) — *the first winner of American Idol (2002); three Grammy Awards; over 25 million albums sold; host of The Kelly Clarkson Show (Daytime Emmys 2020, 2021, 2022). Kelly Rowland (born 1981) — Destiny's Child member; four Grammy Awards. Kelly Ripa (born 1970) — Live with Kelly and Mark*; over $20M annual salary, one of TV's highest-paid hosts. Kelly Slater is male (surfer).
Subject of countless American Idol retrospectives.
In Pythagorean numerology the letters of Kelly reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.