General practitioner (GP) prescribing of psychotropic medicines to paediatric patients is increasing across countries, sparking the need for additional research into this field. We examined prescribing rates, GP and patient characteristics and indications associated with prescribing psychotropic medicines to paediatric patients in Australian general practice, using data from the Bettering the Evaluation and Care of Health (BEACH) program. We extracted all encounters with children aged 3 to 17 from 2000 to 2016. Psychotropic medicines were defined as those in the ATC codes N05 (Psycholeptics) and N06 (Psychoanaleptics). Of the 144,397 encounters, GPs prescribed 1829 psychotropic medicines to paediatric patients at an average rate of 1.16 prescriptions per 100 encounters (95% confidence interval 1.09–1.23). We found that the rate of psychotropic medicines prescribed to paediatric patients in Australian general practice increased. Patients who were adolescent, female, socio-economically disadvantaged or from an English-speaking background were significantly more likely to be prescribed a psychotropic medicine. GP practices in remote or regional areas and Australian graduate GPs were more likely to prescribe psychotropic medicines to paediatric patients. Depression, attention deficit hyperactivity disorder, anxiety and autism were the most common psychiatric indications managed with psychotropic medicines. Antidepressants, psychostimulants, benzodiazepines, antipsychotics and other psychotropic medicines were prescribed, signifying a high rate of off-label use. Sertraline was the most common psychotropic medicine prescribed, followed by fluoxetine and methylphenidate. Future studies involving data from other prescribers, e.g. paediatricians and psychiatrists, and studies linking prescribed medicines to their indications may widen our understanding of psychotropic medicine prescribing in Australian paediatric patients.