Dubs have topped disposable income rankings every year since 2012 and earned 4.7pc more than Limerick residents in 2019, who earned the second most.
Limerick had the second highest income level in 2019 of €24,540, at 11.4pc above the state average. When rent is factored into disposable income, Limerick comes out as the county with more disposable income, on average, than any other county, usurping Dublin by approximately €500.
Dubliners in 2019 earned 16.6pc more than the average State income of €22,032, which was largely bolstered by the four highest earning counties. Average incomes in Dublin, Limerick, Kildare and Cork are the only four counties that are above the State average of €22,000.
Wicklow earned right on the average while all other counties earned less than average.
The midlands counties of Laois, Longford and Offaly earned the least in the nation with average disposable incomes of just three quarters of those of Dublin averages.
All three counties had an average disposable income of less than €17,000 in 2019. These three counties and Westmeath saw incomes decreased by €69 in 2019.
The Border region had the second-lowest average disposable income per person at 15.9pc below the State average. Donegal experienced an average income of less than €17,500 in 2019.
The gap between the highest and lowest regions has grown in recent years, John Milne, Statistician for the CSO, said.
"The gap between the highest and lowest value of per capita disposable income on a regional basis increased from €7,205 in 2018 to €8,571 in 2019 due to average Dublin incomes increasing by €1,297, while incomes in the Midlands decreased by €69.
"Incomes in all other regions rose between 2018 and 2019.
"Dublin, Limerick, Kildare and Cork, in that order, were the only counties where per capita disposable income exceeded the state average in 2019, while Westmeath, Donegal, Offaly, Longford and Laois earned significantly less than the state average," Mr Milne said.
Of the €156bn total household income across the nation, Dublin accounted for 35pc of it, or €54bn.