This report offers an overview of research that has been conducted in the area of Indigenous mental health, particularly as it relates to the mental health of those who come into contact with the criminal justice system. The purpose of the report is to assist the Victorian Department of Justice with developing appropriate responses in the area of Indigenous mental health across the justice system. It begins by considering the relationship between the criminal justice and mental health systems, the disability sector, and policy frameworks that will help guide Indigenous-focused policy and practice at this interface. The document is then divided into four parts: part I examines available Indigenous mental health data in the general population and the criminal justice population, with comparison to non-Indigenous groups where possible; part II provides an overview of Indigenous conceptualisations of mental health and illness, principally the Social and Emotional Wellbeing Framework; part III reviews mainstream conceptualisations of mental health and illness, and critically examines their capacity to understand and meet the needs of Indigenous clients of the criminal justice and mental health systems currently; and part IV focuses on service responses that follow logically from the foregoing analysis, both in terms of wellness and illness dimensions of mental health.