President Michael D Higgins will lead tributes later to the leaders of the 1916 Easter Rising.
A state commemoration takes place each year in Arbour Hill, the final resting place of the seven signatories of the Proclamation of the Republic.
This year the event will take place in two locations, with a significant portion in Áras an Uachtaráin.
The commemoration will get under way when President Higgins rings the Peace Bell followed by a wreath laying ceremony.