Many scholars assert that Indigenous peoples across the globe suffer a disproportionate burden of mental illness. Research indicates that colonialism and its associated processes are important determinants of Indigenous peoples’ health internationally. In Canada, despite an abundance of health research documenting inequalities in morbidity and mortality rates for Indigenous peoples, relatively little research has focused on mental health. This paper provides a critical scoping review of the literature related to Indigenous mental health in Canada. We searched eleven databases and two Indigenous health-focused journals for research related to mental health, Indigenous peoples, and Canada, for the years 2006–2016. Over two hundred papers are included in the review and coded according to research theme, population group, and geography. Results demonstrate that the literature is overwhelmingly concerned with issues related to colonialism in mental health services and the prevalence and causes of mental illness among Indigenous peoples in Canada, but with several significant gaps. Mental health research related to Indigenous peoples in Canada overemphasizes suicide and problematic substance use; a more critical use of the concepts of colonialism and historical trauma is advised; and several population groups are underrepresented in research, including Métis peoples and urban or off-reserve Indigenous peoples. The findings are useful in an international context by providing a starting point for discussions, dialogue, and further study regarding mental health research for Indigenous peoples around the world. •Most research addresses colonialism; more nuanced approaches are recommended.•Overemphasis of substance use problems and suicide can have negative implications.•Mental health services developed by Indigenous communities are most effective.•Inuit are overrepresented in research; Métis are drastically underrepresented.•Urban and off-reserve Indigenous populations are dramatically underrepresented.