C15

C15 or C.XV may refer to:
 * Albatros C.XV, a 1918 German military reconnaissance aircraft
 * BSA C15, a unit-construction motorcycle manufactured by the Birmingham Small Arms Company between 1959 and 1967
 * Coronado C15, a sailboat
 * HMS C15, a 1908 British C-class submarine
 * Sauber C15, a 1996 racing car
 * Citroën C15, a light van
 * IEC 60320 C15, a power connector
 * The 15th century (1401–1500)
 * McDonnell Douglas YC-15
 * Esophageal cancer ICD-10 code
 * Carbon-15 (C-15 or 15C), an isotope of carbon
 * Caldwell 15 (NGC 6826), a planetary nebula in the constellation Cygnus
 * A 15-minute Cassette tape, often used to store computer games
 * A synthetic chemerin-derived peptide