A National Day of Commemoration ceremony has been held at the Royal Hospital Kilmainham in Dublin, while ceremonies are also planned at several other locations across the country.
The multi-faith and military ceremony honoured all Irishmen and Irishwomen who died in past wars or on service with the United Nations.
The Dublin event was attended by President Michael D Higgins, Taoiseach Enda Kenny, the Government and Council of State.
Members of the Diplomatic Corps, Defence Forces, veterans' organisations, the Judiciary and representatives from Northern Ireland also attended.
Ceremonies will also take place in Cork, Galway, Kilkenny, Limerick, Waterford and Sligo.