- (Greek mythology) The ship in which Jason and the Argonauts sailed on their quest for the Golden Fleece.
- (astronomy) Argo Navis, a large constellation in the southern hemisphere, now divided into Carina, Puppis, and Vela.
- The Argo. (mythical ship)
Fourth declension, with irregular nominative in -ō. Only the genitive and accusative are attested. The remaining forms have been reconstructed based on the Greek inflection.
- Argo in Charlton T. Lewis & Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
- Argo in Félix Gaffiot (1934), Dictionnaire Illustré Latin-Français, Paris: Hachette.
- Argo in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
- (Greek mythology) Argus (giant with a hundred eyes)
- (Greek mythology) Argo (mythical ship of the Argonauts)