C11, C.XI, C-11 or C.11 may refer to:

Transport

  • C-11 Fleetster, a 1920s American light transport aircraft for use of the United States Assistant Secretary of War
  • Fokker C.XI, a 1935 Dutch reconnaissance seaplane
  • LET C-11, a license-build variant of the Soviet Yakovlev Yak-11 trainer aircraft
  • C-11 Gulfstream II, the military designation of the Gulfstream II business jet
  • Barroso (C11), a light cruiser of the Brazilian Navy
  • HMS C11, a 1907 British Royal Navy C class submarine
  • HMS Liverpool (C11), a 1937 British Royal Navy Town class light cruiser
  • JNR Class C11, a class of Japanese steam locomotives
  • USS Marblehead (C-11), an 1892 light cruiser of the United States Navy
  • BSA C11, a British motorcycle manufactured between 1939 and 1956
  • Mercedes-Benz C11, a 1990 Group C prototype race car
  • London Buses route C11, a public transportation route in England
  • LNER Class C11, a class of British steam locomotives
  • Leapmotor C11, a mid-size electric crossover SUV

Science and technology

  • C11 (C standard revision), standardized version of the C programming language
  • Head and neck cancer (ICD-10 code)
  • Eye diseases, (MeSH code); see List of MeSH codes (C11)
  • Carbon-11, an unstable isotope of the chemical element Carbon
  • Caldwell 11, the Bubble Nebula, an emission nebula in the constellation Cassiopeia

Other uses

  • C11 (rifle), a competition and training weapon used by members of the Royal Canadian Army Cadets
  • C11 Right of Association (Agriculture) Convention, 1921
  • Bill C-11, various articles of legislation of the Parliament of Canada
  • French Defence (Encyclopaedia of Chess Openings code)
  • 11th century

See also

  • 11C (disambiguation)