Gnathophis smithi is an eel in the family Congridae (conger/garden eels). It was described by Emma Stanislavovna Karmovskaya in 1990. It is a subtropical, marine eel which is known from the Nazca and Sala y Gómez ridges, in the southeastern Pacific Ocean. It dwells at a depth range of 145-250 metres, and leads a nocturnal lifestyle. Males can reach a maximum total length of 41.1 centimetres. The eel's diet includes benthic crustaceans and polychaetes. The species epithet refers to David G. Smith, noted for specializing in the study of eels.