A shotgun was a type of weapon. Shotguns were typically a projectile weapon, firing using gas-pressure to launch either multiple small bits of metal shot, or a single large slug as a projectile. These weapons were available in automatic, semi-automatic, and non-automatic models, with projectile caliber measured in "gauges". These weapons were used for sport, offense or defense by the Humans of Earth starting around the era of the industrial revolution. Shotguns are typically deadly at a short range, and often an effective irritant at a distance. (ENT episode: "In a Mirror, Darkly")

In 2268, the Melkotian recreation of 19th century Human John Holliday used a shotgun in a gunfight. (TOS episode: "Spectre of the Gun", TOS novelization: The Last Gunfight)