The Firearms Act 1968 (c. 27) is a UK act of Parliament, controlling use and possession of firearms.

Since 1968, the act has been extensively amended. Following the Hungerford massacre, the Firearms (Amendment) Act 1988 extended the class of prohibited weapons. Following the Dunblane school massacre, two acts were passed, the Firearms (Amendment) Act 1997 and, after the general election that year, the Firearms (Amendment) (No. 2) Act 1997, which in effect banned almost all handguns. The Policing and Crime Act 2017 brought clarity to aspects of the act, following a recommendation from the Law Commission.

Section five of part one of the act states that a prohibited firearm is one which;^[1]

• Fires more than one projectile when the trigger is pressed
• Is a self-loading or pump-action rifled gun except when chambered for 5.6 mm rim-fire cartridges;
• Has a barrel shorter than 30 centimetres or is shorter than 60 centimetres overall, except air weapons, muzzle-loading gun or signalling firearms
• Is a self-loading or pump-action smooth-bore gun which is not an air weapon or chambered for 5.6 mm rim-fire cartridges and has a barrel shorter than 60 cm or shorter than 100 cm overall
• Is a smooth-bore revolver gun except chambered for 9 mm rim-fire cartridges or a muzzle-loading gun
• Is a rocket launcher or mortar except when designed for line-throwing, pyrotechnic purposes, or for signalling
• Air firearm which uses a self-contained gas cartridge system; i.e., the Brocock system of pump-up cartridges, each with their own pellet, but not a CO₂ bulb system.
• Weapon of whatever description designed or adapted for the discharge of any noxious liquid, gas or other, presumably including sound or light that may cause injury

For ammunition it is prohibited if it;^[1]

• Are designed to explode on or immediately before impact
• Contain any such noxious item
• Consists of a missile

Prohibited firearms and ammunition may only be possessed, purchased, sold, given, or manufactured with authority from the government; as enacted this was from the Defence Council, as of 2020 this is from the Secretary of State.^[1]

• Firearms regulation in the United Kingdom