O'Neills Irish International Sports Company Ltd. was established in 1918. It is the largest manufacturer of sportswear in Ireland and has manufacturing plants in Dublin and Strabane.
O'Neills has a long relationship with Irish rugby, soccer and Gaelic Athletic Association. O'Neills also produces amateur boxing kits (vests and shorts). They are currently kit suppliers to a number of inter-county teams in both Gaelic football and hurling including Antrim GAA, Cork GAA, Dublin GAA, Kerry GAA, Mayo GAA, Kilkenny GAA, Tipperary GAA, Galway GAA, Down GAA, Donegal GAA, Tyrone GAA, Roscommon GAA Meath GAA and Offaly GAA
The O'Neill brand has become synonymous with the production of team kits, footballs and sliotars (hurling and shinty balls) for Gaelic games but is fast becoming a major supplier to rugby and soccer clubs across Ireland, Great Britain, Europe and North America. O'Neills was the exclusive supplier to the Irish Provinces for many years and to the Irish international teams during their Triple Crown era.