O'Mooney

O'Mooney is an Irish surname derived from the Gaelic Ó Maonaigh, meaning "descendant of Maonaigh." The personal name Maonaigh itself translates to "wealthy," reflecting a probable ancestral association with prosperity or land ownership. This surname is a classic example of the Irish patronymic tradition, where the prefix Ó (grandson or descendant) combines with a given name to form a family lineage.

The O'Mooney surname is primarily associated with the province of Connacht, particularly counties Galway and Roscommon, though variations depending on Anglicization are common. The name is closely related to Meaney and Mooney, both of which are anglicized forms of the same original Ó Maonaigh. The spelling variant O'Mooney emerged during the 18th and 19th centuries as Irish names were transcribed into English records, often influenced by scribes' interpretations of pronunciation. Migration during the Great Famine spread the name to the United States, the United Kingdom, and beyond.

• Meaning: “descendant of Maonaigh” (wealthy).
• Origin: Irish (Gaelic).
• Type: Patronymic surname.
• Regions: Connacht, especially Galway and Roscommon.