Kasilof is a census-designated place located in the U.S. state of Alaska. It lies in Kenai Peninsula Borough 12 miles of south Kenai along Kasilof River. Kasilof coordinates at 60°20′7″N 151°14′1″W with an elevation of 125 feet. Kasilof was previously a detachment of Russians employed by the Lebedev-Lastochkin Company. There were 549 total residents as of 2010 census data. The population density was 49/sq mi. It has Zip code 99610 and Area code 907.