CMN may refer to: Canadian Museum of Nature, in Canada's National Capital Region Carmarthen railway station, Wales, station code CMN Catholic Media Network, Philippines radio network Centre des monuments nationaux, French heritage agency Certificate of medical necessity, in American healthcare Children's Miracle Network Hospitals, in the U.S. and Canada College of Menominee Nation, in Wisconsin, U.S. Common Music Notation, open source musical notation software Constructions Mécaniques de Normandie, a shipyard in Cherbourg, France Mohammed V International Airport, Casablanca, Morocco, IATA code CMN Mandarin Chinese, ISO 639-3 language code cmn See also Carmarthenshire, county in Wales