That's according to the latest Census figures.
The latest Census figures show that there were over 5.1 million people in the State on Census night, which took place in April last year.
That is an 8% (387,274 people) increase on April 2016 figures.
County Kildare's population increased by 11%, while the county continued to be one of the counties with the youngest age on average, at 36.9.
Nationally, the population includes more females than males.
There are 2.6 million females living in the country compared to 2.5 million males.

Friday's Kfm Obituary Announcements
New Cultural Programme Set For Castletown House
Celbridge Woman Who Lost Sister To CF Calls For People To Support Today's Fundraiser
Protestors, Including Kildare's John Dallon, Refused Entry From Government And Agriculture Bodies Meeting
Defence Forces Travelling To The Curragh Today For Training
Newbridge Silverware’s Silver-plated Cutlery Factory Officially Closes
Martin Heydon Will Meet Farming And Haulier Groups This Morning Amid Fuel Protests
Missing 17-Year-Old Joshua Treacy From Maynooth Has Been Located