Social isolation, exposure to suicide, and overweight increase suicidal ideation in adolescents, but no study to date has examined their relative significance in American Indian and Alaska Native (AI/AN) youth. Generalized estimating equations and path analyses were used to measure the significance and mediation of these variables in the suicidal ideation of 721 AI/ANs and 12,107 White adolescents. Social isolation, exposure to suicide, and overweight were risk factors for suicidal ideation in both races, and the associations among the variables of interest and suicidal ideation varied by race. Interventionists need to consider race in the prevention of suicidal ideation in AI/AN and White youth.