Cancer is the leading cause of death among Alaska Native (AN) people, and the third leading cause of years of potential life lost. AN tribal health leaders and researchers want to understand the cancer burden attributable to modifiable risk factors among AN people, to inform the design of cancer prevention strategies that may reduce the burden of these diseases. To address this question, we estimated the population attributable risk (PAR) associated with modifiable risk factors for cancer including obesity, smoking, physical inactivity, and alcohol use, among AN people. We observed that PAR varied by cancer site and risk factor, but was highest for lung cancer and smoking, with an estimated 78.8% of cancers among males, and 69.8% among females attributable to this risk factor. A smaller, but still substantial proportion of cancers were associated with obesity (up to 37% for endometrial cancer among females), physical inactivity (up to 18% for endometrial cancer among females), and alcohol use (up to 34% for breast cancers among heavy drinking females). These results demonstrate the importance of smoking as a primary prevention target to reduce the burden of cancer and other chronic diseases among AN people. However, they also indicate that obesity, physical activity, and alcohol use may also account for a varying, but substantial proportion of cancers in this population. Given the high burden of cancer among AN people, a comprehensive approach to primary prevention is warranted.