Key may refer to:

• Key (lock), a device used to open a lock
• Key (company), a Japanese visual novel studio
• Keying (vandalism), paint scratching
• Key Bank, a bank
• Key (comics), a DC Comics supervillain
• Key Club International, a worldwide student service organization

In music:

• Key (instrument), musical intruments have keys for tuning and keys for playing
  • "Keys" is also a clipped form of "keyboard instruments"
• Key (music), a set of notes
• Key signature, in musical notation

In computers:

• A button on a computer keyboard
• Primary key or foreign key, in databases
• Key (cryptography), a piece of information that controls the operation of a cryptography algorithm
• The index into a hash table
• Keying (graphics), an informal term for compositing two full frame images together
• USB key, a computer storage device

In geography:

• The legend on a map
• Cay, a small, low island
• key, a small, low island
• Florida Keys
• Key (woreda), a district in the Southern Nations, Nationalities and Peoples' Region of Ethiopia.

See also Quay.

Key might also refer to:

• Churchkey, used for opening metal cans
• Key plate, in printing, a plate which printed the detail in an image
• Key frame, in animation, a frame made by an animator from which other frames are derived
• Keychain, small chain that connects a small item to a keyring
• Keyword, a term referring to a specifical word employed for different meanings
• Identification key, a method of deducing the correct species assignment of a living thing
• House of Keys, the lower branch of the Isle of Man's Parliament
• An area on a basketball court
• Francis Scott Key, author of the United States national anthem - "The Star-Spangled Banner."
• Telegraph key, the button used by a telegraph operator
• The Keys to the Kingdom, a fantasy-adventure book series
• Keyblade, the main weapon of the main character of the Kingdom Hearts series, Sora.

Clau | Schlüssel (Begriffsklärung) | Κλειδί | Clave | Clef | Chiave | Sleutel | キー (曖昧さ回避) | Klucz | Chave | Ключ