The Footprint of Mental Health Conditions: Healthy Brains at Work is the first of a four-part series that explores the importance of addressing mental health and mental illnesses in Canadian workplaces. This initial briefing begins by providing a profile of mental health and mental illness in Canada, including a detailed look at the prevalence of mental illness in the employed population. The importance of addressing poor mental health in the workplace is explored, along with an introduction to existing, evidence-based tools, programs, and treatments that are, or can be, used by employers. In sum, this briefing creates a foundation for the series by synthesizing what we know about mental illness in the workplace, and why employers should address this burden through evidence-based programs and treatments. The second briefing in this research series will explore the extent to which employers are leveraging resources and tools and providing appropriate supports.