Leahy is an Irish surname, originating in Munster, and now found in Cork, Kerry, Limerick, and Tipperary. Anglicised from the Irish Gaelic Ó Laochdha ('descendant of Laochdha'),:191 it ultimately derives from Old Irish láechda, láech ('warrior-like, pertaining to a warrior') which appears as a personal sobriquet at least as early as the Book of Lismore.
Notable bearers of the name
- Bernie Leahy (born 1960), Bishop of Limerick.
- Con Leahy (1880–1921), Irish athlete
- Edward Daniel Leahy (1797–1875), Irish painter
- Edward L. Leahy (1886–1953), United States Senator
- Frank Howard Lahey MD (1880–1953), surgeon, medical educator, and founder of Boston's Lahey Clinic
- Frank Leahy (1908–1973), American football player and coach, athletics administrator and sports executive
- Sir John Leahy (diplomat) (1928–2015), British diplomat
- John Leahy (executive) (born 1950), American businessman, executive at Airbus
- John O'Lahy (executed 5 Jul 1581), sailor, and one of the Wexford Martyrs
- Kevin Leahy (disambiguation)
- Margaret Leahy (1902–1967), British actress
- Michael Leahy (disambiguation)
- Patrick Leahy (disambiguation)
- Peter Leahy (born 1952), Chief of the Australian Army
- Sean Leahy (born 1958), Australian cartoonist
- Sir Terry Leahy (born 1956), English businessman
- William D. Leahy (1875–1959), American naval officer and ambassador
- William Leahy (Australian Army soldier) (1893–1918), Australian World War I Distinguished Conduct Medal recipient
- William Harrington Leahy (1904–1986), United States Navy admiral
- William P. Leahy (born 1948), President of Boston College
- MacLysaght, Edward (2005) . The Surnames of Ireland (6th ed.). Dublin: Irish Academic Press.
- "láechda". eDIL: Electronic Dictionary of the Irish Language, c. 700–c. 1700. 2016. Retrieved 12 Aug 2016.
- Lahaie, Richard (2013). "Le Premier Couple Irlandais de Nouvelle-France". Histoire Québec. 18 (3): 15–18.
- Woulfe, Patrick (1922). Sloinnte Gaedheal is Gall: Irish Names and Surnames. Baile áta Cliat: M. H. Mac an Goill 7 a Mác.