Sea Dragon
- Common seadragon
- Dragon (disambiguation)
- Dragonfish (disambiguation)
- Francisco José do Nascimento
- Glaucus atlanticus
- Ichthyosauria
- Kairyū-class submarine
- Leafy seadragon
- MH-53E Sea Dragon
- Majipoor series
- Operation Sea Dragon (Vietnam War)
- Phyllopteryx
- Richard Halliburton
- Ruby seadragon
- SSM-700K C-Star
- Sea Dragon (rocket)
- Sea Dragon (roller coaster)
- Sea Dragon (video game)
- Sea Dragon-class ROV
- Sea Monsters (disambiguation)
- Sea serpent
- Seadragon Software
- Subnautica
- Thalassiodracon
- Thalassodraco
- The Dragon in the Sea
- USS Seadragon