Portlaoise has overtaken Athlone as the largest town in the Midlands region.
Census figures released late last week show that the population of Portlaoise increased by nearly 10 per cent to 22,050 in the period 2011 to 2016.
Athlone saw its population increase at the lesser rate of 5.9 per cent during the same period, rising from 20,153 to 21,349 people.
Mullingar comes in as the third largest town in the Midlands, with a population increase from 20,103 in 2011 to 20,928 in 2016 - a rise of 4.1 per cent.
Tullamore had a population of 14,607 in April 2016 compared to 14,361 in April 2011, amounting to an increase of 246 persons or 1.7 per cent.
The settlement of Ballymahon had a population of 1,877 in April 2016 compared to 1,563 in April 2011, rising by 314 persons or 20.1 per cent.
Athlone remains both the largest and fastest growing of all towns in Westmeath. The findings also show that 51 per cent of people living in Westmeath are located in rural areas.
To view the full publication visit www.cso.ie/en/census/