Neptune can refer to different things:

• Neptune, the planet
• Neptune, the god in Roman mythology
• Neptune, New Jersey
  • Neptune Township, New Jersey
  • Neptune City, New Jersey
  • Neptune, California , a fictional coastal town near San Diego, California and the setting for Veronica Mars
• "Neptune, the Mystic" is a movement in Gustav Holst's The Planets suite.
• Neptune , a fictional miniature submarine in the James Bond film For Your Eyes Only.
• One of the Soviet operations in the Battle of Stalingrad
• Neptune, convict ship in Second Fleet, to New South Wales.