Suicide rates among Aboriginal peoples in Canada are several times higher than rates among the non-Aboriginal population. Based on data from the 2012 Aboriginal Peoples Survey, this article presents prevalence estimates of suicidal thoughts among First Nations living off reserve, Mtis and Inuit aged 26 to 59. It examines associations between suicidal thoughts and mental health, socio-demographic and other characteristics, many of which have been shown to be related to suicidal thoughts in other populations. In 2012, more than one in five off-reserve First Nations, Mtis and Inuit adults reported having ever had suicidal thoughts; only among Mtis did a difference emerge between men and women, with women more likely to report such thoughts. Women in all three Aboriginal groups were more likely than non-Aboriginal women to report suicidal thoughts. Compared with non-Aboriginal men, off-reserve First Nations and Inuit men were also more likely to have had suicidal thoughts. Self-reported, physician-diagnosed mood and/or anxiety disorders; drug use; and lack of high self-worth were associated with suicidal thoughts in all three groups and both sexes. Factors such as heavy, frequent drinking; being widowed, divorced, separated or never married; and not being in excellent or very good health were associated with suicidal thoughts among some, but not all Aboriginal groups and sexes. Personal or familial residential school experience was marginally associated with suicidal thoughts among Mtis women when each Aboriginal group and sex was examined separately. When all Aboriginal groups and males and females were combined, residential school experience was significantly associated with suicidal thoughts. These results could inform further research that can be used to guide suicide prevention programs among First Nations, Mtis and Inuit.