Hydra generally refers to:

• Lernaean Hydra, a many-headed serpent in Greek mythology
• Hydra (genus), a genus of simple freshwater animals belonging to the phylum Cnidaria

Look up Hydra or hydra in Wiktionary, the free dictionary.

Hydra or The Hydra may also refer to:

• Hydra (constellation)
• Hydra (moon), a satellite of Pluto

• Hydra (chess), a chess computer
• Hydra (digital repository), an open-source digital repository software product later renamed Samvera
• Hydra (operating system), an early, discontinued, capability-based, object-oriented microkernel
• Hydra (software), a parallelized network login cracker built in various operating systems
• Hydra (specification), a specification for REST APIs
• Hydra 100, a multi-GPU hardware solution
• HYDRA Game Development Kit, a development system by André LaMothe
• Razer Hydra, a game controller
• NEC HYDRAstor, a storage system

• Hydra (comics), a fictional organization in the Marvel Universe
  • Hydra (Marvel Cinematic Universe), an organisation in the Marvel Cinematic Universe based on the comics counterpart
• Hydra (Dungeons & Dragons), a fictional monster in D&D
• Hydra (Transformers), a character in Transformers
• The Hydra, a fictional organization in The Phantom
• Hydra, a character in UFO Ultramaiden Valkyrie
• The Hydra, a fictional deity created by Henry Kuttner
  • Mother Hydra, the co-ruler of the Deep One race in the Cthulhu Mythos
• The Hydra, a fictional fighter jet in Grand Theft Auto: San Andreas and Grand Theft Auto Online
• The Hydra, a fictional machine in Kirby Air Ride
• Hydra, a boss enemy in the video game Prototype 2

• Hydra (film), a 2008 monster movie
• Hydra (Chuck), a fictional database on Chuck
• Hydra, a fictional Dharma Initiative station on Lost

• Hydra Entertainment, the hip-hop record label
• Hydra (band), an American southern rock band in the 1970s
• Hydra (E.P.), an E.P. by British ambient duo Main (band), 1991
• Hydra (Otep album), 2013
• Hydra, an album by Satariel, 2005
• Hydra (Toto album), or the title song, 1979
• Hydra (Within Temptation album), 2014
• Hydra, an album by Iris, 2008
• "Hydra", a song by Dir En Grey from Macabre, 2000
• "Hydra", a song by Twilight Force from Dawn of the Dragonstar, 2019
• "HYDRA", a song by Myth & Roid, 2018
• "The Hydra", a song by Le Sserafim from Antifragile, 2022

• Hydra (skater), roller derby skater
• Hydra (wrestler), American professional wrestler
• Hydra, an alias of DJ and producer The Thrillseekers

• Hydra, Algeria, a neighbourhood and a municipality in Algiers
• Hydra (island), an island of Greece

• Hydra (ship), a hydrogen ship
• Greek ironclad Hydra, a French-built ironclad warship launched in 1889
• Greek destroyer Hydra, a Dardo-class destroyer launched in 1932
• Greek frigate Hydra, a MEKO 200-type frigate launched in 1992, lead ship of the Hydra class frigate
• HMS Hydra (1797), a 38-gun fifth rate
• HMS Hydra (1838), a wooden steam paddle sloop
  • Hydra-class sloop, a class of British steam sloops
• HMS Hydra (1871), a Cyclops-class turret ship
• HMS Hydra (1912), an Acheron-class destroyer
• HMS Hydra J275), an Algerine-class minesweeper launched in 1942
• HMS Hydra (A144), an oceanographic survey vessel launched in 1965
• Hydra-class minelayer, a class of Dutch 1910s minelayers
• HNLMS Hydra (A854), a Duch Navy diving support vessel

• The Hydra, a literary magazine
• Hydra (association), a German self-help and advocacy group for prostitutes
• Hydra (video game), an arcade and Atari Lynx video game
• Hydra game, a concept in mathematical logic
• Hydra Market, a Russian language dark web marketplace that facilitated trafficking of illegal drugs as well as financial services
• Hydra the Revenge, a roller coaster at Dorney Park in Pennsylvania, US
• Hydra 70, an air-to-ground rocket
• Hydra Technologies, an unmanned aerial vehicle firm
• Hydra Trophy, a trophy of the roller derby WFTDA Championships
• Hydra, a wireless station during World War II at Camp X
• Operation Hydra (Yugoslavia)
• Operation Hydra (1943)

Wikimedia Commons has media related to Hydra.

• Greek ship Hydra, a list of Hellenic Navy vessels
• HMS Hydra, a list of British Navy vessels
• Hydro (disambiguation)
• Hydrus, a small constellation in the deep southern sky
• Ghidra, reverse engineering software
• All pages with titles beginning with Hydra
• All pages with titles containing Hydra

This disambiguation page lists articles associated with the title Hydra.
If an internal link led you here, you may wish to change the link to point directly to the intended article.