Lionfish may refer to:

• Genus Pterois, collectively known as the lionfish
• Red lionfish (P. volitans), a significant invasive species off the East Coast of North America and in the Caribbean

Fish

• a number of fish species within family Scorpaenidae, mostly found in the Indo-Pacific:
  • Brachypterois serrulata, also known as the Pygmy Lionfish
  • within genus Dendrochirus, collectively known as the dwarf lionfishes
    • Dendrochirus barberi, known as the Hawaiian Lionfish or Green Lionfish
    • Dendrochirus biocellatus, known as the Fu Chu Lionfish or Twinspot Lionfish
    • Dendrochirus brachypterus, known as the Hawaiian Lionfish
    • Dendrochirus zebra, known as the Zebra Lionfish
  • within genus Ebosia:
    • Ebosia bleekeri, also known as Bleeker's Lionfish
  • within genus Parapterois:
    • Parapterois heterura, also known as the Blackfoot Lionfish
  • within genus Pterois, collectively known as the lionfish:
    • Pterois antennata, also known as the Antennata Lionfish
    • Pterois miles, also known as the African Lionfish or Mombasa Lionfish
    • Pterois radiata, also known as the Clearfin Lionfish, Tailbar Lionfish, or Radiata Lionfish
    • Pterois volitans, also known as the Red Lionfish

Other

• USS Lionfish (SS-298), a United States Navy submarine