The Glasnevin Trust is holding an Armistice Day memorial to erect headstones for war dead who served in the British defence forces in the world wars.
The Trust last month published details of the 43 men and women who served in both world wars and are buried in unmarked graves in Glasnevin Cemetery.
Family members of the deceased were asked to contact the Trust ahead of today's ceremony.
The project of marking the graves was started last year on Armistice Day and headstones were erected at the graves of four Irish servicemen for the first time.
Ecumenical and military ceremonies were due to take place at the O'Connell Tower, Glasnevin Cemetery.
Glasnevin Trust historian Shane MacThomais researched the stories of the 43 deceased.
He went to Britain's National Archives in Kew, England, where he researched the military records.
There he uncovered considerable detail about the personal and military lives of the servicemen and women spanning from the Boer War, Chinese Boxer Rebellion, Zulu Wars, and World War I and II.
Most of the graves date back to World War I with the oldest of the 43 burials in 1914 and the most recent in 1947.
Families may wish to contact Mr MacThomais who has additional information about the deceased or use the online genealogical search facility that contains full burial records www.glasnevintrust.ie/genealogy.'
Elsewhere, several hundred people have attended a Remembrance Day event in Belfast to commemorate those who died in the two world wars and conflicts since then.
SDLP Mayor of Belfast Pat Convery and leading members of the Royal British Legion observed a two-minute silence at Belfast City Hall.
Former members of the British armed forces were among the crowd of onlookers.