Kasilof (/kəˈsiːlɒf/ kə-SEE-lof; Dena'ina: Ggasilat, Russian: Касилов) is a census-designated place (CDP) in Kenai Peninsula Borough, Alaska, United States.

[4] Kasilof first appeared on the 1880 U.S. Census as an unincorporated village named "Kassilof.

In 1786 a detachment of Russians employed by the Lebedev-Lastochkin Company built an artel at the location of modern Kasilof for fishing operations.

While it likely received expansions, it "never played a significant role in the history of the Russian colonies.

During the establishment of the Russian-American Company, a fur monopoly in Russian America, the assets of the LLC were liquidated.

A partial excavation of the area in 1937 found 31 well-preserved houses from the settlement.