It is an offence to carry an offensive weapon or possess a dangerous article without a lawful excuse [Summary Offences Act 1953 (SA) s 21C]. For more information about weapons offences, see Common offences - weapons.

Knives

It is an offence to sell a knife to a minor under the age of 18 [Summary Offences Act 1953 (SA) s 21D(1)]. This age was raised from 16 to 18 on 1 July 2025. The maximum penalty is a fine of up to $20,000 or imprisonment for 2 years.

A knife for the purposes of this offence does not include

[See Summary Offences Regulations 2016 (SA) reg 8(1).]

It is a defence if the person selling the knife requested a prescribed form of evidence of age, such as a driver's licence or proof of age card, and the minor made a false statement or produced false evidence of their age, resulting in the sale [see s 21D(2)].

It is also an offence to market a knife for sale or hire in a way that indicates or suggests (by its name or description) the knife is suitable for combat or is otherwise likely to encourage the use of the knife as a weapon [Summary Offences Act 1953 (SA) s 21D(4)]. The maximum penalty is a fine of up to $20,000 or imprisonment for 2 years.

From 1 July 2025, it is an offence to supply a knife to a minor if the seller knows or ought to know that the minor intends or is likely to use the knife

Serious offence of violence is defined for the purposes of s 21DA and includes an offence against the Criminal Law Consolidation Act 1935 (SA) in which harm, serious harm or death is caused [Summary Offences Act 1953 (SA) s 21DA(3)].

Firearms

It is an offence to possess a firearm without a firearms licence [Firearms Act 2015 (SA) s 9]. A person under the age of 18 cannot usually hold a firearms licence [s 14(3)] but some exceptions apply.

A child aged between 12 and 17 years who is a member of a recognised firearms club and needs to hold a firearms licence for competitions held in another state or country may obtain a category 1 (shooting club) licence for 3 years [Firearms Regulations 2017 (SA) reg 14(7)].

A child aged between 15 and 17 years whose employer or relative is the operator of a business in primary production may obtain and hold a category 5 (primary production) licence for an A or B class firearm, but may not acquire a firearm [reg 18(4)].

Children aged 10 to 14 years may use a registered firearm (category A or air handgun) under the continuous supervision of a guardian (or other person approved by their guardian) who holds an appropriate licence for the purpose for which the firearm is being used [s 8].

Children 14 to 17 years may also use a registered firearm (category A, B or H) under the continuous supervision of a guardian (or other person approved by their guardian) who holds an appropriate licence for the purpose for which the firearm is being used [s 8].

There is also provision for very specific circumstances relating to coaching, sporting and theatrical or film productions [reg 40].