Mental health and behaviour problems are the most common set of associated conditions for individuals with ASD across the lifespan, placing tremendous burden on the individual and family, as well as on the educational, community, vocational, and healthcare systems. Up to 70% of individuals with ASD are estimated to have mental health problems. We need to provide better treatment and care to people with ASD who are at risk for, or develop, mental health problems. Over the next five years, I aim to implement a Canada-wide, strategic research program to improve the mental health of people with ASD. I will focus on the individual with ASD, their family, and the service system. I will identify risk factors for mental health problems in individuals with ASD by following children, adolescents, and adults with ASD over a three-year period, measuring mental health at 6-month time points. I will conduct treatment research by providing a novel therapy to help youth with ASD who have been traumatized by chronic bullying and have mental health problems, evaluating and refining the treatment, and teaching trainees and clinicians how to provide therapy to people with ASD. I will also study how family caregivers access services for people with ASD across the country, and identify the gaps in care. The Chair support will allow me to conduct specific foundational studies, engage with a broad range of stakeholders on an ongoing basis, translate the knowledge gained to inform policy and practice, and train and mentor the next generation of researchers and practitioners in state-of-the-art methods to improve treatment and care for individuals with ASD in Canada. In the end, this Chair will have a substantial impact on the health and well-being of Canadians with ASD and their families.