IK or Ik may mean:

• IK Investment Partners, a European private equity firm
• Imran Khan, Pakistani politician and former cricketer
• Inupiaq language (ISO 639 alpha-2), a group of dialects of the Inuit language, spoken in Alaska
• Ik people of Uganda
  • The Ik language
• Ik River in Russia
• IK code, a classification of resistance to mechanical impacts
• an abbreviation for Inverse kinematics, a branch of mechanics
• an acronym for Index Kewensis, a publication maintained by the Royal Botanic Gardens, Kew
• an abbreviation for Iparretarrak, the Basque nationalist organization
• the IATA airline designator of Imair Airlines
• the regional code for Ilm-Kreis in Germany
• an abbreviation for the German term Internationale Kerze (international candle), an old photometric unit to measure luminous intensity
• a Dutch word for "I" (the first-person singular personal pronoun in the subject case)
• an abbreviation for the computer game International Karate
• Indigenous knowledge, another name for traditional knowledge such as that held by indigenous peoples

International Karate +, often abbreviated as IK+, is a karate fighting video game published in 1987 by System 3, originally for the Commodore 64, Amstrad CPC and ZX Spectrum. It has since been ported to a number of other platforms. The Commodore 64 version was released in the U.S. under the title Chop N' Drop.