The number of students attending private school has risen by 1,5000 in the past five years.
Figures released to the Irish Times show 27,200 pupils were enrolled in private secondary schools last year.
The figure has now surpassed the last peak during the Celtic Tiger in 2008, when over 26,500 students were enrolled.
The highest fees in the state charged by a private school for day students are €8265 at the Cistercian College, Roscrea which has 265 students.
