What is the migrant population in Republic of Ireland?

As of 2019, the Central Statistics Office estimated the migrant population in the Republic of Ireland at 680,068, or 13.6% of the total population. This number includes both foreign nationals and Irish citizens who were born abroad. The highest number of migrants (111,305) were Irish citizens born in the UK. The largest group of foreign nationals was from the United Kingdom (80,622), followed by Poland (53,630) and Romania (38,705).