C74 or C-74 may be:
C-74 Globemaster, transport aircraft with transoceanic range In lighting, a reversed clothespin used to hold gels and light screens in theatrical productions Comiket 74, The 74th Comiket Convention in Japan Ruy Lopez (Spanish Game) opening, Encyclopaedia of Chess Openings Adrenal tumor ICD-10 code Cycling '74, a software development company known for distributing Max/MSP Caldwell 74 (NGC 3132, the Eight-Burst Nebula, or the Southern Ring Nebula), a planetary nebula in the constellation Vela