Enumerators will begin collecting census forms from every household in the country today.
Everyone present in the country last night must have a form filled out and have it ready for collection.
Anyone who refuses to take part in the census faces prosecution and a fine of up to 44 thousand euro.
#Census2016 was trending on Twitter last night, and here are a few of our favourite tweets!
Oh! I never saw that question. Would you class that yoke as a 'PC' I wonder? #Census2016
— irishmammies (@irishmammies) April 25, 2016
In the end, chickened out and dropped down to Ordinary Level Census. Piece of piss. #Census2016
— Colm O'Regan (@colmoregan) April 24, 2016
Grafton St - Woman on phone: "I can't meet later because we're having a census party." #Census2016
— Overheard in Dublin (@OverheardDublin) April 24, 2016
— Ciamhie Mc Digital (@CiamhieMc) April 24, 2016