O’ Sheahan, O’ Sheehan, O’ Shehane, Sheahan, Ó Síodhacháin
Ó Síodhacháin comes from the Gaelic word “siodhach” which means ‘peaceful’. The Ó Síodhacháin sept originated in the barony of Lower Connello in Co. Limerick, and was part of the Dál gCais tribal grouping. The family subsequently migrated to north-east Co. Cork where they are still very numerous. Today the name is ranked as the seventy seventh most popular in Ireland, favouring counties Limerick, Cork, Kerry and Clare.