There were 6,181 children waiting for a primary care psychology appointment at the end of January 2018.
Some 1,635 of them have been waiting over a year to be seen.
The figures were provided to Fianna Fáil Mental Health Spokesperson James Browne.
"To have over a quarter of these children waiting for an appointment for more than a year is just not right," said Deputy Browne.
"Time is of the essence when dealing with vulnerable children and teenagers. The state and the HSE have a duty to do better by these children.
"As ever there are significant regional variations in figures but Cork seems to be the worst affected as it is for so many services.
"Cork has some 466 children waiting over a year - it also has the worst waiting times for the CAMHS service.
"Incidentally the figures do not tell the whole story as there is a ‘data gap’ for Louth and consequently no information for that county is available.
"Renewed efforts need to be made to address these waiting lists. Such deficiencies in mental health services for children cannot be allowed to continue."