Some 40 per cent of the residents of Gort, Co Galway, are now non-Irish nationals, according to the latest analysis of Census 2006 information by the Central Statistics Office.
The fondness of Cork people for their county is also highlighted in the census, which shows that almost eight of 10 Cork residents were born there.
Census figures show that Dublin is the county with the highest proportion of non-Irish nationals at 13 per cent, or 150,000 people, followed by Galway at 10.7 per cent.
Co Kilkenny has the lowest proportion of non-Irish nationals at 7 per cent.
However, small rural towns such as Gort, Ballyhaunis and Ballinrobe in Mayo and Ballyjamesduff in Cavan are the towns with the greatest percentage of non-Irish nationals.
Gort's large Brazilian population accounts for more than 83 per cent of its 1,065 immigrants. The meat industry attracted the first group of skilled workers from Brazil to the Galway town in the 1990s .
Some 36 per cent of Ballyhaunis residents are non-Irish with most coming from eastern Europe. More than 25 per cent of people in Ballinrobe and Ballyjamesduff are from overseas.
Clara, Co Offaly, is the town with the smallest percentage of non-Irish nationals, at 3.8 per cent, or 111 people. The CSO did not include towns with less than 1,500 inhabitants in this analysis.
Census 2006 was conducted on the night of April 23rd last year and found that almost 10 per cent of the State's residents were non-Irish nationals.
More than 191,331 had arrived in the country since 2002, with 122,000 arriving in the 12 months before the census.
Some 65 per cent of the State's 4.2 million population still live in the county in which they were born but this rises to 76.9 per cent for Cork, followed by Donegal at 73.5 per cent.
At the other end of the scale, just four out of 10 people living in Meath and Kildare were born there. CSO statistician Brian King said this was explained by the large number of commuters living in these counties.
He also pointed to the changing face of the family unit as highlighted in these latest statistics. The number of non-Irish families has more than doubled in recent years, going from 20,187 in 2002 to 50,655 last year.
The vast majority of these families included a husband and wife with children. Cohabiting couples with children only account for 1,876 non-Irish national families.
Meanwhile, the number of mixed nationality families increased from 70,721 in 2002 to 95,636 in 2006. The majority of immigrants who moved to Ireland in the 12 months before the census are single (68.2 per cent) and in their 20s (62.2 per cent).
