Gnathophis tritos is an eel in the family Congridae (conger/garden eels). It was described by David G. Smith and Robert H. Kanazawa in 1977. It is a marine, deep water-dwelling eel which is known from the Straits of Florida, in the western central Atlantic Ocean. It dwells at a depth range of 458-567 metres. Gnathophis tritos was given its species epithet due to its being the third species in its genus discovered in the western Atlantic.