ODN may refer to: Optical Distribution Network, the physical fibre and optical devices that distribute signals to users in a telecommunications network. Ordnance Datum Newlyn, the mean sea-level height datum in Great Britain. CpG Oligodeoxynucleotide also known as a CpG ODN, a molecule with immunostimulatory properties. Open DOS Navigator, an orthodox file manager for DOS Orbital Data Network, a public safety satellite network.