Kodiak Island Borough is a borough in the U.S. state of Alaska. At the 2020 census, the population was 13,101, down from 13,592 in 2010. The borough seat is Kodiak.

The City of Kodiak is the main city and one of seven communities on Kodiak Island in Kodiak Island Borough, Alaska. All commercial transportation between the island's communities and the outside world goes through this city via ferryboat or airline. As of the 2020 census, the population of the city is 5,581, down from 6,130 in 2010. It is the tenth-largest city in Alaska.