HCN
HCN may refer to:
- Hydrogen cyanide, that has chemical formula HCN
- Highly composite number, a type of integer
- Headcorn railway station, that has British National Rail code HCN
- Halcyon Air/Bissau Airways , that has ICAO code HCN
- the IATA airport code of Hengchun Airport
- Cyclic nucleotide-gated ion channel, the molecular species which mediates the h-current in neurons.