KN may stand for:
- Complete graph of size, denoted
- Croatian kuna, the official currency of Croatia (currency sign Kn or kn)
- Democratic People's Republic of Korea (NATO country code KN)
- Kannada language (ISO 639-1 language code kn)
- Khuddaka Nikaya, the fifth nikaya (collection) of the Sutta Pitaka division of the Buddhist Pali Canon
- Kid Nation, a show on CBS
- Kieler Nachrichten, a newspaper printed in Kiel, Germany
- Kilonewton (kN), an SI unit of force
- Klein-Nishina formula, a formula for prediction of the angular distribution of x-rays and gamma rays incident upon a single electron
- Knot (unit) (kn), nautical miles per hour
- Knudsen number (Kn), in physics
- Kühne + Nagel, a logistics company
- Saint Kitts and Nevis (ISO 3166-1 alpha-2 country code KN)
- .kn, the country code top level domain (ccTLD) for Saint Kitts and Nevis
- Kilingi-Nõmme, Estonia
- Kohtla-Nõmme, Estonia
- Karksi-Nuia, Estonia