Within the UK and Ireland, the surname Osullivan most frequently occurs in Ireland where it is carried by 1 in every 2,054 people. The majority of those with the family name of Osullivan are to be found living in/around Munster, Leinster and, to a lesser extent, Connaught. The name can also be found in England with 1 in 83,928 people using it.
This website uses cookies to ensure you get the best experience. Read our privacy policy for more about what we do with your data as well as your rights and choices.