C17

C17, C-17 or C.17 may refer to:

Transportation

 * HMS C17, a 1917 British C-class submarine

Air

 * Boeing C-17 Globemaster III, a military transport aircraft
 * Lockheed Y1C-17 Vega, a six-passenger monoplane
 * Cierva C.17, a 1928 English experimental autogyro

Land

 * C-17 highway (Spain) also known as Eix del Congost, a primary highway in Catalonia
 * Queensland C17 class locomotive
 * Sauber C17, a 1998 Formula One car

Science and technology

 * C17 (C standard revision), an informal name for ISO/IEC 9899:2018, the most recent standard for the C programming language
 * C17, a female two-pole IEC 60320 electrical cable connector that mates with a male C18 appliance inlet
 * Caldwell 17, a dwarf spheroidal galaxy of the Local Group in the constellation Cassiopeia
 * Carbon-17 (C-17 or 17C), an isotope of carbon
 * C17, a 17-Carbon molecule in chlorophyll metabolism
 * Precorrin-3B C17-methyltransferase, an enzyme involved in that metabolism
 * Small intestine cancer (ICD-10 code)

Other uses

 * City 17, a fictional location in the Half-Life universe
 * French Defence (Encyclopaedia of Chess Openings code)
 * 17th century
 * Android 17, character from Dragon Ball Franchise