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.

Kfm Obituary Notices
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Kilcullen Library To Extend Its Opening Times From Today
12th Lock To Hazelhatch Greenway Has Officially Opened
Banished Temple Bar St. Patrick Statue Makes Surprise Return in Kildare Parades
Man Charged In Connection With Serious Assault On North Main Street In Naas