Thalassa is a personification of the sea in Greek mythology.

Thalassa may also refer to:

  • Thalassa (band), a band which represented Greece at the Eurovision Song Contest 1998
  • Thalassa (beetle), a genus of ladybug
  • Thalassa (moon), a moon of the planet Neptune
  • Thalassa (TV series), a French documentary programme
  • , a ship of the Ifremer
  • A fictional planet in Arthur C. Clarke's novel The Songs of Distant Earth
  • A character from the Star Trek original series episode "Return to Tomorrow"
  • Thalassa Gramarye, a fictional musician in the video game Apollo Justice: Ace Attorney

See also

  • Thalassia (disambiguation)
  • Thalasso (disambiguation)
  • Thalassocracy
  • Thalassotherapy
  • Panthalassa
  • Thalatta! Thalatta!