Suicide is a major public health issue in Japan, with very high rates of death compared to other countries in the Asia Pacific. Foreigners living in Japan may be at increased risk of suicide, but little is known about how their risk of suicide differs from that of their country of origin or Japanese nationals. We used data on suicide mortality from the Japan Vital Registration System for the period 2012–2016 to analyze risk of suicide mortality in Japan for Japanese, Korean, Chinese, and other nationalities living in Japan, adjusting for age and separately by sex. We estimated standardized mortality rates using both the Japanese population as a reference, and also the population of the home nation of the foreign residents. We found that Korean nationals living in Japan have significantly higher mortality rates than Japanese nationals, and that the suicide mortality rate of Korean nationals living in Japan is higher than in their home country, but that this is not the case for Chinese or other nationals resident in Japan. Koreans living in Japan have a very high risk of mortality due to suicide which may reflect the special social, economic, and cultural pressures they face as a marginalized population in Japan.