That’s according to provisional data released by the Minister for Education and Skills for the 2015 to 2016 academic year.
The information was released by Minister Richard Bruton following a parliamentary question by Sinn Fein Offaly TD Carol Nolan.
The provisional data which relates to mainstream classes only is based on the National School Annual Census.
In this academic year there were 15,865 primary school pupils in Kerry.
Of those 20 per cent or almost 3,300 (3,248) pupils were in classes of thirty or more.
60 per cent or around 9,300 (9,369) were in classes of 25 or more.
Around 100 Kerry pupils were in classes of nine or less.
Nationally two thirds of primary school pupils were in classes of 25 or more.