Seal or SEAL can refer to:

• Seal, a device used to produce an official stamp as a symbol of authority. Origin: Latin `sigillum' = "small symbol".
• Seal: a deposit of (usually) sealing wax on a document: fastening it closed and/or with a seal stamp impression on it.
• Seal, a mechanical device to contain pressure, or exclude contamination from an enclosure. This meaning derives from the previous meaning.
• Seal, a type of pinniped, a large marine fish-eating mammal. Origin: Anglo-Saxon 'seolh'.
• Seal, a British soul vocalist, who has released three eponymous albums:
  • Seal (1991 album)
  • Seal (1994 album)
  • Seal (2003 album)
• Seal, a village in Kent in England.
• U.S. Navy SEALs, a SEa, Air, Land team of the United States Navy
• SEAL, (Semantics-directed Environment Adaptation Language), a computer language
• SEAL, a cryptographic cipher