Voting in the Presidential election and the blasphemy referendum begins this morning.
Polling stations will be open between 7am and 10pm this evening.
After a largely low-key campaign people will have the chance today to elect the President of Ireland.
Incumbent Michael D Higgins is seeking re-election to Áras an Uachtarain - the first sitting President to actively campaign for a second term.
Also on the ballot are Sinn Féin MEP Liadh Ni Riada and Independent Senator Joan Freeman.
The three businessmen Peter Casey, Seán Gallagher and Gavin Duffy will also be options when people enter the polling booth.
The expectation is that turnout will be low after a lacklustre campaign.
Votes are also being cast in the referendum on blasphemy.
Ms Justice Isobel Kennedy, Chairperson of the Referendum Commission, is encouraging citizens to use their vote today.
A Yes vote would mean deleting the reference to blasphemy in the constitution, allowing the Oireachtas to get rid of the criminal offence of blasphemy.
A no vote would leave the constitution as it is currently.
Voters are advised to bring their voting card and official ID with them to the polling centres.
Reporting by Sean Defoe