Ketchum is a city in Blaine County, Idaho, United States, in the central part of the state. The population was 2,689 at the 2010 census, down from 3,003 in 2000. Located in the Wood River Valley, Ketchum is adjacent to Sun Valley and the communities share many resources; both sit in the same valley beneath Bald Mountain, with its world-famous skiing. The city also draws tourists from around the world to enjoy its fishing, hiking, trail riding, tennis, shopping, art galleries, and more.