Saccopharynx thalassa is a species of ray-finned fish within the family Saccopharyngidae. Its known to live in the Eastern Atlantic near Madeira and the Canary Islands, and the Western Atlantic near Bermuda at depths up to . It grows to a length of . It has been classified as a 'Least concern' species by the IUCN Red List, as it has a wide distribution with no known major threats.