From Irish Mac Aodha meaning 'son of Aodh (fire)'; a surname adopted as a given name.
Mccoy comes from the Irish and Scottish Gaelic surname McCoy, more traditionally written McCoy, an Anglicized form of Mac Aodha. That Gaelic patronymic means "son of Aodh," and Aodh was an old personal name associated with fire; in Irish tradition it could also refer to a deity-name carried into early medieval naming. So beneath the brisk modern surname style, Mccoy carries a very old Celtic root, one tied to kinship and to the vivid image of fire.
As a first name, it belongs to the wider Anglo-American habit of turning surnames into given names, especially names that sound sturdy, brisk, and unmistakably distinctive. Culturally, McCoy is unusually rich for a surname-name. It recalls the Hatfield-McCoy feud, one of the most famous family rivalries in American folklore, and it also echoes the phrase "the real McCoy," meaning the genuine article.
That idiom gives the name an accidental charm: authenticity is built right into its aura. Some people also think of the inventor Elijah McCoy, whose achievements may have helped reinforce that phrase in popular memory, even if the expression’s exact origin is debated. As a given name, Mccoy feels more recent and more American than ancestral; it has the crisp confidence of a surname chosen for style, but the roots are much older and more Gaelic than they first appear. Over time it has shifted from clan identifier to personal statement, sounding adventurous, energetic, and faintly frontier-like while still carrying old Celtic embers underneath.