In response to concerns regarding overprescribing of psychotropic medication in children/adolescents, this study examined trends in psychotropic medication use in Ireland by age group and gender. A retrospective, repeated, cross-sectional study of the Irish pharmacy claims database was conducted. Yearly prevalence of children/adolescents receiving dispensed psychotropic medications was analysed from January 2017 to December 2021 and compared across years, age groups (5-15 years, and stratified as 5-11 and 12-15 years) and gender. Yearly prevalence was defined as the mean number of patients in receipt of medication per month per 1000 eligible population during a given calendar year. Negative binomial regression was used to examine the association of year, age group and gender on prevalence. Prevalence ratios (PRs) per year (average change in prevalence between each year) were presented with 95% confidence intervals (CIs). The prevalence of included psychotropic medications dispensed in the 5-15 years group increased from 6.41 (95% CI: 6.22, 6.59) in 2017 to 8.46 (95% CI: 8.26, 8.68) in 2021 per 1000 eligible population (32% increase). The PR per year (adjusting for age category and gender) was 1.07 (95% CI: 1.035, 1.107; p < 0.001). An increasing trend over time was also observed for all individual drug classes. These findings suggest increased use of psychotropic medication in children/adolescents from 2017 to 2021. However, despite increased prevalence over time, comparison with the literature shows that psychotropic medication use in Ireland remains lower than international comparators.