one in 5 children suffer from mental illness within ontario, with little information known about the 0 to 6 year old population and service provision outcomes. this paper presents the definition and prevalence of mental illness among children aged 0 to 6 years old, identifies services provided for addressing children’s mental health issues in ontario for this population, and presents evidence related to the outcomes of such services. discussion and recommendations for both practice and future research in the area of children’s mental health are provided, with some final thoughts to conclude the paper.