CNX

CNX may refer to:


 * IATA code of Chiang Mai International Airport, Thailand
 * CNX (TV channel), a defunct television channel operating in Britain from 2002 to 2003
 * CNX Resources, natural gas company formerly part of Consol Energy
 * OpenStax CNX, an educational content repository based at Rice University
 * Middle Cornish, ISO 639-3 language code cnx
 * Vagus nerve, the tenth cranial nerve, abbreviated CN X