Kelly

Kelly is a surname and a given name of Irish origin. It derives from the Gaelic Ó Ceallaigh, meaning “descendant of Ceallach,” a personal name of uncertain meaning that is often associated in later interpretations with war or brightness. The surname has long been established in Ireland and is widespread among descendants of the Irish diaspora. Variants include Kelley and Kellie, among others.

As a given name, Kelly is predominantly feminine in contemporary usage, though there are historical male instances in Ireland and Scotland. In the United States, the name rose in popularity in the mid-20th century and remains common for girls, with usage in other English-speaking countries as well.

Notable people with the surname include Grace Kelly (1929–1982), American actress who became Princess of Monaco, and Kevin Kelly (born 1952), writer and editor. Notable people with the given name include Kelly Clarkson (born 1982), American singer and first winner of American Idol; Kelly Slater (born 1972), American professional surfer; Kelly Rowland (born 1981), American singer and Destiny’s Child member; and Kelly Reichardt (born 1964), American filmmaker.

In other contexts, the name Kelly appears in mathematics as the Kelly criterion, a formula for optimal bet sizing in gambling and investments, named after John L. Kelly Jr. The name also occurs in various place names and institutions, typically deriving from individuals bearing the surname.