C13 or C-13 may refer to:

Science and technology

  • IEC 60320 C13, a polarised, three pole plug used in electric power cables
  • Caterpillar C13 Engine, an engine by Caterpillar Inc.
  • Caldwell 13 (NGC 457, the Owl Cluster or ET Cluster), an open star cluster in the constellation Cassiopeia
  • Carbon-13 (<sup>13</sup>C), a natural stable isotope of carbon
  • Malignant neoplasm of hypopharynx (ICD-10 code), a head and neck cancer
  • Tridecylic acid, a saturated fatty acid

Military and transportation

  • C13 grenade, the Canadian Forces designation for a M67 grenade
  • Autovia C-13, a highway in Catalonia, Spain
  • HMS C13, a 1906 British C-class submarine
  • LNER Class C13, a steam locomotive class

Other uses

  • Sauber C13, a 1994 racing car
  • 13th century
  • C13, in music, a chord with the structure 1 - 3 - 5 - b7 - 9 - 13
  • French Defence (Encyclopaedia of Chess Openings code)
  • C13 White Lead (Painting) Convention, 1921, an International Labour Organization Convention