McIlhenny or McElhenny is an Irish surname commonly found in Donegal and Derry also found in the highlands of Scotland. They are a Sept of the Cenel Eogain race, son of Naill high king of Ireland. In Gaelic the name translates "servant of Saint Canice". Notable people with the surname include:
Don McIlhenny (born 1934), American football playerEdward Avery McIlhenny (1872–1949), American businessman and Arctic explorerEdmund McIlhenny (1815–1890), American businessman and inventor of Tabasco sauceHenry Plumer McIlhenny (1919–1986), American art collectorJohn Avery McIlhenny (1867–1942), American businessman, Rough Rider, and politicianPaul C. P. McIlhenny (1944–2013), American businessman and conservationistWalter Stauffer McIlhenny (1910–1985) American businessman and World War II Marine