Defender may refer to:

• Organizations:
  • Defenders of the Egg, a Gorn fleet.
• Starships and vehicles:
  • Federation:
    • Defender-class, a 23rd century battleship class in the prime reality.
    • Defender-class, a 23rd century bomber class in the alternate reality.
    • USS Defender (NCC-26227), a Miranda-class starship in the 23rd century.
    • USS Defender, an Akira-class starship in the 24th century.
  • Romulan:
    • Heavy Defender-class, a Romulan starship class in the 23rd century.
    • Winged Defender-class, a Romulan starship class in the 23rd century.
    • ChR Defender, a Romulan starship in the 23rd century.
    • RIS Defender, a Romulan starship in the 24th century.
  • Klingon:
    • Defender-class, a Klingon starship class in the 23rd century.
    • IKV Defender
  • Borg harmonic defender, a Borg starship class in the 24th century.
• Titles:
  • Defender
• Real-world topics:
  • Captain Proton: Defender of the Earth, an anthology of Captain Proton stories.