The surname Walsh is among the four most numerous surnames in Ireland, behind Murphy, Kelly and Sullivan. It is found in every county and is particularly strong in Mayo, where it has first place, and also in Galway, Cork, Wexford, Waterford and Kilkenny.
The name originated to describe the Welsh people who came to Ireland during the Anglo-Norman invasions and simply means the ‘Welshman’, or in Irish ‘Breathnach’. The name is often pronounced ‘Welsh’ in Connaught and Munster. The first use of the surname is said to have been Haylen Brenach, alias Walsh, son of ‘Philip the Welshman’, one of the invaders of 1172. He is recorded as being with Strongbow, earl of Pembroke, in his initial invasion of Ireland in that year. The Walshes in the south-east of Ireland are mostly descended from Philip the Welshman and also from his brother David. Many of this family established themselves as landed gentry at Castlehowel (Kilkenny), Ballykileavan (Laois), at Ballyrichmore (Waterford) and also at Bray and Carrickmines near Dublin.
According to Lawrence Walsh who compiled the pedigree of the Tirawley (Mayo) Walshes in 1588, the Walsh family in the west of Ireland are believed to be descended from Walynus, a Welshman who came to Ireland with Maurice Fitzgerald in 1169. This man’s brother, Barrett, was also believed to be the ancestor of the Barretts of Tirawley.
The surname Walsh has lent itself to many place names throughout Ireland and is to be found in at least 13 counties as far apart as Mayo, Down, Kilkenny and Cork. Examples of this are Walshtown, Walshpark, Walsh Mountains in Kilkenny etc. Under its Irish guise the name can be found in counties Carlow, Down, Cork and Kerry, in place names such as Ballybrannagh and Ballinabrannagh, amongst others.