Background: Mental health problems is an important contributor to the global burden of disease. Exposure to intimate partner violence (IPV) and violence in childhood (CV) is associated with mental health problems. These issues are scarcely studied among the Sami. This study estimates the prevalence of IPV and its association to mental health problems among Sami and non-Sami, and whether the effect of IPV on mental health was altered by exposure to CV. To our knowledge, this is the first population-based study estimating IPV and its association to mental health problems among Sami and non-Sami in Norway. Methods: This study was based on the cross-sectional SAMINOR 2 Questionnaire Survey, a part of the Population-based Study on Health and Living Conditions in Regions with Sami and Norwegian Populations – the SAMINOR Study. Pearson’s chi-square tests and two-sample t-tests were used for testing differences between groups and multiple linear regression analysis was applied to explore the association between IPV/CV and mental health problems (continuous scores of psychological distress and symptoms of post-traumatic stress). Results: A total of 12.8% of women and 2.0% of men reported to have experienced any IPV (emotional, physical, and/or sexual). A significantly higher proportion of Sami women reported exposure to emotional (12.4% vs. 9.5%, p=.003), physical (11.6% vs. 6.9%, p<.001), and any IPV (17.2% vs. 11.8%, p<.001) compared to non-Sami women. There were no ethnic differences in sexual IPV among women (2.1% vs. 1.8%, p=.5). The study demonstrated that being exposed to emotional, physical, or sexual IPV is associated with mental health problems. The most severe mental health problems were observed among those who reported both IPV and CV. There were no ethnic differences in the association between the different types of IPV and mental health problems, and we observed overall similar results among men and women. Conclusions: The most severe mental health problems were observed for those who were exposed to both IPV and CV. It is therefore important for victims of IPV to address experiences of violence in childhood. The effect that IPV and CV have on mental health problems seems to be same, regardless of ethnicity and gender.