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, K_f, related to freezing-point depression
• Karl Fischer titration
• Stability constants of complexes, abbreviated as K_f (constant of formation)
• Filtration coefficient.

Sports

• Knattspyrnufélag Fjallabyggðar, an Icelandic sports team