Two referenda, on judicial pay and Oireachtas investigations, are also being voted on, as is the Dublin West by-election following the death of former Minister for Finance Brian Lenihan earlier this year.
Just over 3.1 Million people are entitled to vote in the two elections and the two referenda.
The electorate will be asked to choose their top three candidates for the presidency in order of their preference while the referendum are based on a yes or no answer. Voters in Dublin West will also use the single transferable vote system.
That is every Irish citizen over the age of 18 who is included on the Register of Electors or the Supplementary Register.
Most people should have received a polling card by now, but even if you have not you are still entitled to vote as long as you are registered.
However, you may be asked for identification at your local polling station.
Acceptable forms of identification include a passport, driving licence, an employee or student identity card with a photograph, or a bank or credit union book showing an address in the constituency.
You can also use a cheque book or card, a credit card, or a birth or marriage certificate, if you also have another document showing you live in the constituency.