King Salmon is a census-designated place in Bristol Bay Borough in the U.S. state of Alaska. It is 284 miles southwest of Anchorage. As of the 2020 census the population was 307, down from 374 in 2010. It is home to Katmai National Park and Preserve. King Salmon is the borough seat of neighboring Lake and Peninsula Borough, but does not serve that purpose in its own borough, whose borough seat is in Naknek.