- Proper noun. (Greek mythology) The mythological Greek warrior who slew the Gorgon Medusa by decapitating her. He married Andromeda after rescuing her from Ceto and founded Mycenae. He was the son of Jupiter and Danae.
- Proper noun. (constellation) An autumn constellation of the northern sky, said to resemble the mythical hero. It includes the stars Algenib and Algol.
- Proper noun. The last Antigonid king of Macedonia, Perseus of Macedon.