Nine Kerry primary schools have pupils in classes of 35 students or more.
The information, compiled by the Department of Education, shows Kerry to have among the greatest number of students in overcrowded classrooms per population.
According to the primary school lists for the last academic year, nine Kerry primary schools have pupils in classes comprising between 35-39 students.
The average nationwide is just under 25 pupils per class.
The greater Killarney area is particularly affected, with Glounaguillagh, Lissivigeen, Firies and Fossa National Schools all having students in classes exceeding 35 students.
Listowel Presentation Primary, St Finian’s in Waterville, Scoil Naisiunta Treasa Naofa in Kilflynn and Scartaglin National School are also named by the department.
Gaelscoil Mhic Easmainn in Tralee has 109 students in classes exceeding 35 students; this is the second highest nationwide.