Polling stations are now open across the country with two referendums on same sex marriage and the age of the President being decided today.
You can vote from now until 10pm.
Voters are being reminded not to spoil their vote by drawing or writing on the ballot paper.
A selfie could potentially spoil your vote, as would wearing clothes or badges that advertise your view.
Chairman of the Referendum Commission Judge Kevin Cross says a simple 'X' in the Yes or No box will do:
