Objective: To investigate the patterns and the determinants of mental health service use by children and adolescents in Australia. Method: Data from Young Minds Matter (YMM): The Second Australian Child and Adolescent Survey of Mental Health and Wellbeing is used in this study. YMM is a face-to-face household survey conducted in 2013–2014 that collected information from 6310 parents/carers of children aged 4–17 years (55% of eligible households). A self-reported survey of 2967 (89% of eligible youth) 11- to 17-year-olds from these households was also conducted. Bivariate analyses are used in this study to examine the variables and their distributions over the outcome variables. Binary logit models are used to investigate the determinants of mental health service use. Results: Parent reported data shows that among children aged 4–17 years, 12%, 1.2% and 0.6% utilised health services, school services and telephone services, respectively. Youth reported data reveals that approximately 7.2%, 2% and 4% and 23.5% of children aged 11–17 years used health services, school services, telephone services and online services, respectively. Youth reported data further shows that online services were the most popular type of mental health service among adolescents. Those with anxiety or ADHD constituted the highest proportion of children that used any type of mental health services. Logistic analysis of parent reported data shows that children from step, blended and sole-parent households compared to original parent households were more likely to use any type of mental health service, and the same trend was seen for children living in inner regional areas compared to those living in major cities. Children of parents with lower education or unemployed parents were also more likely to utilise health services. Conclusion: From the findings, it is concluded that age-relevant mental health services should be improved and made available for children and adolescents. Secondly, school and health services should have a particular focus on complex disorders like ADHD, anxiety and conduct disorders, as these are the services most used by children who suffer from these conditions. Finally, areas of low socio-economic status should focus on improving their school and health services as these are the services used most by children from these backgrounds.