KF

KF or Kf may refer to:

Businesses and brands:
 * KF Aerospace, a Canadian aerospace company
 * KF Cargo, a Canadian cargo airline
 * KF Defence Programs, a Canadian defense contractor
 * Korea Foundation
 * Air Belgium, an airline based in Belgium (IATA code KF)
 * Blue1, a defunct airline based in Finland (IATA code KF)
 * Kettle Foods, a snack foods manufacturer
 * Kooperativa Förbundet, a cooperative Swedish retail chain
 * KrisFlyer, the frequent flyer program of Singapore Airlines
 * A member of the Mazda K engine family
 * Kiwi Farms

Games:
 * Katamari Forever, a video game for the PlayStation 3
 * Killing Floor (2009 video game), a cooperative survival horror video game

Science and technology:
 * A member of the Mazda K engine family
 * Kalman Filter, in mathematics
 * Potassium fluoride, a chemical substance
 * Klein Flange, a quick release vacuum flange
 * Cryoscopic constant, Kf, related to freezing-point depression
 * Karl Fischer titration
 * Stability constants of complexes, abbreviated as Kf (constant of formation)
 * Filtration coefficient.

Sports
 * Knattspyrnufélag Fjallabyggðar, an Icelandic sports team