The largest public sector trade union in the Republic of Ireland, with over 35,000 members in health, local government, education, the civil service, state-owned companies, telecommunications, aviation, and the voluntary and community sector.

A trade union for executive grades in the Civil Service and the wider public sector in Ireland, the PSEU was formed in 1890 and has over 7,000 members in the Civil Service, Eircom, An Post, the National Lottery, the Commissioners of Irish Lights, the Irish Aviation Authority, the Health and Safety Authority, the National Pensions Board and FAS.