Argonaut may refer to:

• The Argonauts, a band of heroes who sailed on the ship Argo with Jason in Greek mythology.
• A cephalopod of the genus Argonauta, a kind of octopus.
• Argonaut , Simon Lake's first submarine.
• Two submarines of the United States Navy named USS Argonaut.
• Four ships of the Royal Navy named HMS Argonaut.
• The Argonaut , a passenger train operated by the Southern Pacific railroad between Los Angeles, CA and New Orleans, LA.
• Argonaut Games, a British video game company.
• The Toronto Argonauts, a team in the Canadian Football League.