Okanogan is a city in Okanogan County, Washington, United States. The population was 2,379 at the 2020 census, down from 2,552 at the 2010 census, within the Greater Omak Area. It is the seat of Okanogan County. It has a small commuter airfield, Okanogan Legion Airport – with one paved runway of 2,533 ft in length.