This is a list of laws concerning air guns by country.
Most countries have laws about air guns, but these vary widely. Often each jurisdiction has its own unique definition of an air gun; and regulations may vary for weapons of different bore, muzzle energy or velocity, or material of ammunition, with guns designed to fire metal pellets often more tightly controlled than airsoft weapons. There may be minimum ages for possession, and sales of both air guns and ammunition may be restricted. Some areas in the world require permits and background checks similar to those required for firearms proper.
Australia
The Australian gun law is quite restrictive and differs on a state-by-state basis; however, as a general rule all air guns — regardless of action type, caliber and muzzle energy — are considered firearms for legal purposes; e.g. air rifles are considered Class A firearms and as such are subject to licensing and registration.
Air pistols are considered same as rimfire and centerfire handguns and subjected to Class H firearms restrictions. An air pistol shooter will require membership and sufficient attendance at an authorized pistol club for six months before allowing ownership, and needs to shoot in at least six events per year — and four events per year for each additional handgun class (air pistol, rimfire or centerfire) — the minimum events per year must include at least six formal competitions to keep the licence.
Paintball markers are classified as "soft air weapons" and treated differently to other air guns; refer to the paintball section on legality for a state-by-state breakdown. Paintball markers are classified in NSW as "recreational sporting devices" as of the 1st of July 2019.
Though also regarded as "soft air weapons", airsoft guns are strictly prohibited in all states except in the Northern Territory (where they are considered regular air guns and subjected to the corresponding laws and licensing) and the ACT (where they are considered "imitation firearms").
Brazil
The Brazilian legislation that regulates the manufacture, import, export, trade, traffic and use of air guns used to divide them into two groups: air guns by spring action or pre-compressed air (PCP - Pre Charged Pneumatic) of up to 6mm calibre; air guns by spring action or pre-compressed air (PCP - Pre Charged Pneumatic) of calibre exceeding 6mm; or pre-compressed gases that is not breathable air, such as and others, in any calibre. Until 2010, air guns in the first group may be purchased by anyone over 18. Air guns in the second group could only be purchased by people registered in the army, transportation depended on authorization, and usage was allowed only in places approved by the army. Air guns of any kind may not be carried openly. There was no muzzle energy limit for any type or calibre until 2010.
Until 2010, scopes or any equipment with magnification needed to be registered by the army in the shooter's registry and accompany a traffic authorization, and were allowed to civilians only if under 6 times magnification and with the objective lens smaller than 36 millimeters. Scopes with magnification equal or above 6 times and/or over 35 millimeters, or equipment that mark the target (like laser sights), were restricted to civilians and allowed only for use by the army. The permitted equipment has to be registered in the civilian's document, this process is called "Apostilamento". The document for a shooter's registry is called "Certificado de Registro de Atirador".
Since 2010, there isn't any restriction on caliber for air guns. It is now legal to own any kind of airgun, be It a springer, a PCP or any other kind of air gun, as long as the muzzle energy isn't bigger than 500 Joules.
Also, the restriction for optic devices for air guns were removed and is now required only in some cases, for military-grade equipment. Since February 1, 2023, firearm ownership is now facing new restrictions, but there isn't any new restriction for air gun ownership – they can be used by anyone, and they can be owned by anyone over 18 years old. Since 2010, air guns can also be used anywhere that is safe and the owner/tenant gave his permission. For example, the owner or tenant can shoot his air gun at his backyard, as long as he isn't committing a crime (if he is shooting late at night, he may be committing a crime if he is generating much noise). It's still illegal to open carry an air gun, and even when someone carry his air gun in a concealed way of inside the case, he must prove his ownership of the air gun, likely with a copy of the receipt. All this information can be seen at the Brazilian's army website.