Key points
- Treason is mainly a Commonwealth offence (Criminal Code s 80.1): killing or harming the Sovereign, the Governor-General or the Prime Minister, levying war against the Commonwealth, or getting a non-citizen to invade.
- The maximum is life imprisonment, not a mandatory life sentence (Crimes Act 1914 s 4D).
- Related offences: materially assisting a proclaimed enemy (life, but humanitarian aid is excluded), treachery (life) and urging violence against the Constitution or a government (7 years).
- It applies overseas too, and there is a defence for criticism, pointing out errors and urging lawful change in good faith.
- State laws: Victoria, Tasmania and South Australia still have treason offences; WA deleted its treason chapter in 1988, and the Queensland and NT codes have none.
- If you are being investigated or charged, call 1800 577 015 at any hour: free general legal information, and a 60-minute consultation with a lawyer for a fixed $295.
In Australia, treason is chiefly a Commonwealth offence under section 80.1 of the Criminal Code, covering killing or harming the Sovereign, the Governor-General or the Prime Minister, levying war against the Commonwealth and instigating an invasion; it carries a maximum of life imprisonment, which is a maximum rather than a mandatory sentence.
Checked on 23 October 2026 against the Commonwealth Criminal Code and Crimes Act 1914, and the criminal laws of Victoria, Tasmania, South Australia, the ACT, Western Australia, Queensland and the Northern Territory.
The Commonwealth offences
| Offence | What it covers | Maximum penalty |
|---|---|---|
| Treason (s 80.1(1)) | Causing the death of, harming, imprisoning or restraining the Sovereign, the Governor-General or the Prime Minister; causing the death of the Sovereign's heir apparent or consort; levying war, or any act preparing to levy war, against the Commonwealth; instigating a person who is not an Australian citizen to make an armed invasion of the Commonwealth or a territory | Life imprisonment |
| Treason (s 80.1(2)) | Receiving or assisting someone you know has committed treason so they can escape; knowing someone intends treason and not telling police within a reasonable time or using other reasonable efforts to prevent it | Life imprisonment |
| Treason by assisting an enemy (s 80.1AA) | An Australian citizen or resident (or a person under the Commonwealth's protection, or an Australian company) intentionally and materially assisting an enemy that the Governor-General has proclaimed to be engaged in armed conflict involving Australia or its Defence Force. Humanitarian aid is excluded | Life imprisonment |
| Treachery (s 80.1AC) | Using force or violence intending to overthrow the Constitution, or the government of the Commonwealth, a state or a territory | Life imprisonment |
| Urging violence (s 80.2) | Urging another person to overthrow the Constitution or a government by force or violence, or to interfere with an election or referendum by force or violence, intending violence to occur | 7 years' jail |
- Life is the maximum, not a mandatory sentence. Under section 4D of the Crimes Act 1914, a penalty set out at the foot of a Commonwealth offence means the offence is punishable by a penalty not exceeding that amount, unless a contrary intention appears.
- Companies: a company convicted of assisting an enemy or treachery can be fined up to 10,000 penalty units.
- Anywhere in the world: the treason offences apply whether or not the conduct, or its result, happens in Australia (ss 80.4, 15.4).
- Good faith: the offences do not apply to someone who, in good faith, tries to show that the Sovereign, the Governor-General or others are mistaken, points out errors in a government, the Constitution, laws or the administration of justice with a view to reform, or urges lawful change (s 80.3).
- State laws still operate alongside these offences where they can (s 80.6).
State and territory treason laws
| Where | State or territory law |
|---|---|
| Victoria | Crimes Act 1958 s 9A: treason (including killing or harming the Sovereign, levying war against the Commonwealth, assisting an enemy at war with it, or forming and showing by an overt act an intention to do so) carries life imprisonment or another term the court fixes. Helping a traitor escape, or failing to tell police of an intended treason, carries up to 20 years. An overt act must be alleged in the indictment. |
| Tasmania | Criminal Code s 56: treason (a list including killing or harming the King, levying war, assisting a public enemy, and any act that is treason under English law) carries life imprisonment or another term the court determines. An accessory after the fact is guilty of treason (s 57), failing to inform a justice of treason is a separate crime (s 58), and a conviction needs two witnesses unless the person pleads guilty (s 60). |
| South Australia | Criminal Law Consolidation Act 1935 s 7: intending and expressing by writing, speech or an overt act an intention to depose the Sovereign, levy war to force a change of policy or overawe Parliament, or to stir a foreigner to invade, carries life imprisonment or a term of not less than 6 months. Section 10A says a person convicted of treason shall be imprisoned for life. Spoken words can only be prosecuted if reported on oath within 6 days and a warrant issued within 10 days, and need a confession in court or two witnesses (s 8). |
| ACT | No treason offence in the Crimes Act 1900, but a person charged with treason is arraigned and tried as if charged with murder (s 280A). |
| Western Australia | The Criminal Code's treason chapter (ss 37 to 43) was deleted in 1988. |
| Queensland and the Northern Territory | Their criminal codes contain no treason offence. |
| New South Wales | We could not read the NSW legislation website on 23 October 2026, so NSW law is not summarised here. |
Free legal help
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General information only, not legal advice. Updated 23 October 2026. Checked against the Criminal Code Act 1995 (Cth) (compilation 174, 30 June 2026), the Crimes Act 1914 (Cth) (compilation 167, 27 August 2026), the Crimes Act 1958 (Vic) (amendments as at 30 September 2026), the Criminal Code Act 1924 (Tas) (version current from 23 December 2025), the Criminal Law Consolidation Act 1935 (SA) (version of 1 July 2026), the Crimes Act 1900 (ACT) (republication 155), the Criminal Code (WA) (as at 1 May 2026), the Criminal Code (Qld) (current as at 1 June 2026) and the Criminal Code Act 1983 (NT) (as in force at 12 October 2026), on 23 October 2026. NSW legislation could not be read that day.