Donegal had the least amount of people jailed last year based on the size of its population.
A total of 5,300 people are jailed across the country.
However, just 42 of these were in Co Donegal.
Nationally, figures released show an average of 89 people 100,000 population were jailed in 2020.
A breakdown, based on the home addresses of the criminals, shows which counties have the highest and lowest rates of imprisonment.
Longford was the most law-breaking county – with an imprisonment rate of 198 people per 100,000 population.
The next lowest rates are Mayo, Leitrim and Offaly.