The Leitrim family of the name were based in the Rosclogher area of the county, around Lough Melvin. Today, the surname is still most common in Leitrim and Clare, with significant numbers also found in the adjacent counties.
.Tom Clancy, (1947- ) is and American thriller writer who specialises in the inclusion of military and technical detail. His best-known book is The Hunt for Red October.
The Clancy Brothers, originally from Carrick-on-Suir, Co. Tipperary, teamed up with Tommy Makem in the 1950s, and played a large part in the revival of traditional Irish music. Although they were part of the international folk music movement, their material drew attention to the Irish originals.
Willie Clancy (1918-1975), from Milltown Malbay in Clare, was famous country-wide for his skill and warmth as a musician (on pipes, flute, fiddle and whistle). When he died another piper, Seamus Ennis, said of him "He died of a big heart".
Peadar Clancy (1901-1920) was one of three prisoners killed in retaliation for the shooting of British agents on "Bloody Sunday" in 1920.