The latest statistics show that Ireland's population is now at its highest level in almost 170 years.
It dropped to 4.4m by the 1861 Census as mass emigration continued in the decades after the Famine of the 1840s.
The latest report by the CSO has shown population growth of 64,500 in the year to April 2019.
It said non-Irish nationals accounted for almost 13% of the total population.
Almost 89,000 people migrated to Ireland in that same period, with just above 30% of those being returning Irish nationals.
Irish natives make up a significant part of those leaving the island, with more than 50% of the 55,000 who emigrated estimated to be Irish.
More than 620,000 residents in Ireland are of non-Irish descent, accounting for nearly 13% of the total population, having increased from 593,600 last year.
All regions have shown a population increase, ranging from 2,600 people (0.5%) in the Mid-West to 25,100 (1.8%) in Dublin.
The capital's population has reached almost 1.4m, which accounts for more than 28% of the total population.
CSO statistician James Hegarty said the combined effect of positive net migration and sustained increase resulted in total of 1.3% population growth.