Muircheartach Óg Ó Súilleabháin (c. 1710 – 1754), was a soldier and smuggler.
Ó Súilleabháin was a native of the Beara Peninsula.
He was serving as a soldier in Spain by 1739, and fought with the Clare's Dragoons at Fontenoy in 1745.
He was a popular figure in local tradition down to recent times.