Despite the importance of indigenous people in the Arctic, there is no accurate estimate of their size and distribution. We defined indigenous people as those groups represented by the "permanent participants" of the Arctic Council. The census in Canada, Russia and the United States records status as an indigenous person. In Greenland, a proxy measure is place of birth supplemented by other information. For the Nordic countries we utilized a variety of sources including registered voters' lists of the various Sami parliaments and research studies that established Sami cohorts. Overall, we estimated that there were about 1.13 million indigenous people in the northern regions of the 8 Member States of the Arctic Council. There were 8,100 Aleuts in Alaska and the Russian North; 32,400 Athabaskans in Alaska and northern Canada; 145,900 Inuit in Alaska, northern Canada and Greenland; 76,300 Sami in northern Norway, Sweden, Finland and Russia; and 866,400 people in northern Russia belonging to other indigenous groups. Different degrees and types of methodological problems are associated with estimates from different regions. Our study highlights the complexity and difficulty of the task and the considerable gaps in knowledge. We hope to spur discussion of this important issue which could ultimately affect strategies to improve the health of circumpolar peoples.