The name Clancy is an Anglicized form of the Irish surname Ó Clónsigh, which is derived from the Gaelic word 'cluain' meaning 'meadow' or 'pasture'. The name originated in Ireland, specifically in the regions of County Clare and County Tipperary, where it was a prominent surname among families of Gaelic Irish descent.

The earliest known historical reference to the name Clancy can be found in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the early 17th century. The annals mention several notable figures bearing the surname Clancy, including Diarmaid Ó Clónsigh, a chieftain of the Dál gCais dynasty who lived in the 10th century.

One of the earliest recorded individuals with the given name Clancy was Clancy of Aughrim, a 12th-century Irish poet and storyteller. His collection of tales and poems, known as the "Book of Clancy", is an important source of Irish folklore and mythology.

Throughout history, several notable individuals bore the name Clancy. One of the most famous was Clancy Brothers, a renowned Irish folk music group active in the 1950s and 1960s. The group consisted of brothers Tom Clancy (1924-1990), Patrick Clancy (1922-1998), Bobby Clancy (1927-2002), and Liam Clancy (1935-2009).

Another prominent figure was Clancy Eccles (1918-1997), a Jamaican singer-songwriter and record producer who helped popularize ska and reggae music. His hit songs, such as "Fattie Burt" and "Jamaican Rocksteady", became classics in the genre.

In literature, Clancy Sigal (1926-2017) was an American novelist and screenwriter known for his works exploring social and political themes, including the acclaimed novel "Going Away" (1961).

The name Clancy was also borne by Clancy Carlile (1888-1968), an Australian aviator and pioneer of early commercial aviation. He established several airlines and air routes in Australia and New Zealand during the early 20th century.

These are just a few examples of notable individuals throughout history who carried the name Clancy, a name with deep roots in Irish culture and a rich legacy spanning centuries.