MacCarthy MacCarthy MacCarthy (Irish: Mac Cárthaigh), also spelled Macarthy, McCarthy or McCarty, is a Gaelic Irish clan originating from Munster, an area they ruled during the Middle Ages. It was and continues to be divided into several great branches. The MacCarthy Reagh, MacCarthy of Muskerry, and MacCarthy of Duhallow dynasties were the three most important of these, after the central or MacCarthy Mór line. Their name, meaning "son of Cárthach" (whose name meant "loving"), is a common surname that originated in Ireland. As a surname, its prevalent spelling in the English language is McCarthy. Several variants are found, such as McCarty
Surname as well as "FitzWilliam" or "Fitzwilliam". Irish surnames are the oldest surnames in Europe. The common prefixes "Ó" and "Mac" can be spelled with the prefix as a separate word, yielding "Ó Briain" or "Mac Millan" as well as the anglicized "O'Brien" and "MacMillan" or "Macmillan". In the United States, 1,712 surnames cover 50% of the population, and about 1% of the population has the surname Smith, which is also the most frequent English name and an occupational name ("metal worker"), a contraction, for instance, of blacksmith or other metalsmiths. Several American surnames are a result of corruptions or phonetic