C18 may refer to:
- HMS C18, a submarine
- Sauber C18, a Formula One racing car
- Caldwell 18 (NGC 185), a dwarf spheroidal galaxy of the Local Group in the constellation Cassiopeia
- French Defence, Encyclopaedia of Chess Openings code
- Combat 18, a British neo-Nazi organization
- The 1938 Chrysler Royal C18
- The C-18, a military cargo version of the Boeing C-137 Stratoliner
- The 18th century (1701–1800 AD)
- an octadecyl-type hydrocarbon with 18 carbon atoms, such as
- IEC 60320 C18, a power connector
- Malignant neoplasm of colon ICD-10 code
|This disambiguation page lists articles associated with the same title formed as a letter-number combination.
If an internal link led you here, you may wish to change the link to point directly to the intended article.