O'Sullivan of Munster – Ua Súileabháin Mhumhain
O'Sullivan Ó Súieabháin originated in South Tipperary before they were forced Westward during the Anglo-Norman invasion where they became one of the leading clans of Munster Eoghanacht. There are a number of sub branches represented by the clan association including:
O'Sullivan Mór
O'Sullivan Beare
O'Sullivan MacCragh
Mac Fineen Duff (extinct)
The cadet clan of MacGillycuddy of Reeks evolved into a separate clan and are listed separately on the Register of Clans.
Website: https://www.facebook.com/groups/osullivanclan
Email: patron@osullivanclan.com