The 57th Fighter-Interceptor Squadron, also known as "The Black Knights of Keflavik", is an inactive United States Air Force unit. The 57 FIS was last stationed at Naval Air Station Keflavik, Iceland. It was inactivated on 1 March 1995.

Naval Air Station Keflavik (NASKEF) is a United States Navy air station at Keflavík International Airport, Iceland, located on the Reykjanes peninsula on the south-west portion of the island. NASKEF was closed on 8 September 2006, and its facilities were taken over by the Icelandic Defence Agency as their primary base until 1 January 2011, when the Agency was abolished and the base handed over to the Icelandic Coast Guard, which has operated the base until 2017. US forces returned to Keflavik in 2016, renovating parts of the base to accommodate P-8As on short duration/expeditionary detachments.