Australian Defamation Law: A State-by-State Guide (2026)

Australian defamation law was uniform from 2005 to 2021. Two reform stages since then split the states and territories apart on serious harm, concerns notices, digital intermediary liability and more, and Western Australia adopted neither stage.

This hub covers civil defamation law as it currently applies across Australia's eight states and territories: New South Wales, Victoria, Queensland, South Australia, Tasmania, the Australian Capital Territory, the Northern Territory and Western Australia. It does not cover criminal defamation, which survives in a narrower form in some jurisdictions, or defamation law outside Australia. Where a rule differs by jurisdiction, this hub links to a dedicated page with the detail.

Is Australian Defamation Law Still "Uniform"?

No. Australian defamation law was genuinely uniform from 2005, when every state and territory enacted a near-identical Defamation Act built from the same national Model Defamation Provisions. That uniformity broke in two stages. "Stage 1" reforms, rolled out from 2021, introduced a serious harm threshold, a mandatory concerns notice precondition to suing, a new public interest defence, a new scientific and academic peer review defence, and repealed the old triviality defence. "Stage 2" reforms, rolled out from 2023, added rules for digital intermediaries such as social media platforms and search engines. Every jurisdiction except Western Australia has now adopted Stage 1. Adoption of Stage 2 is patchier still, and South Australia adopted only part of it. Describing the current law as "Australia's uniform defamation law" is no longer accurate, and this hub avoids that phrase deliberately.

The Adoption Table: Where Each Jurisdiction Stands

The table below is the spine of this cluster. Every fact in it has been checked against the relevant jurisdiction's own consolidated Act on the Australasian Legal Information Institute (AustLII), not assumed to match a neighbouring state.

Two entries above are worth reading twice. The Northern Territory is the only jurisdiction to have gone straight from the unamended 2006 Act to the full reform package in one commencement, on 11 August 2025, rather than adopting Stage 1 and Stage 2 years apart like everywhere else. And Western Australia has an entire row of "No", explained in the next section.

Western Australia Is the Outlier

Western Australia has not adopted either reform stage. Its Defamation Act 2005 (WA) shows no amendment history on the state's own legislation register: it is the Act as originally enacted, with a single currency period running from 1 January 2006. A search for the serious harm provision that exists in every other adopting jurisdiction returns nothing on WA's Act, because the section was never inserted. The practical consequences follow directly from that gap. There is no serious harm threshold in WA, so a plaintiff does not need to prove the publication caused or was likely to cause serious harm to their reputation, the position that applied everywhere in Australia before 2021. There is no mandatory concerns notice precondition, so a person can commence proceedings without first warning the publisher and waiting out a statutory period. There is no public interest defence and no digital intermediary safe harbour. And WA's triviality defence, repealed everywhere Stage 1 was enacted, is still in force there, because the Act that removed it was never enacted in Western Australia. See defamation law in Western Australia for the full detail.

What Stage 1 Actually Changed

Stage 1 made five substantive changes in every jurisdiction that adopted it. It added serious harm as an element of the cause of action, meaning a plaintiff must now show the publication caused, or is likely to cause, serious harm to their reputation, decided by a judge rather than a jury. It made a concerns notice mandatory before suing, giving the publisher a chance to respond or make amends before litigation starts. It introduced a public interest defence, protecting a publisher who reasonably believed publication was in the public interest on a matter of public interest. It introduced a scientific or academic peer review defence for statements in peer-reviewed publications. And it repealed the old triviality defence, which had let a defendant escape liability by showing the plaintiff was unlikely to be harmed. Triviality and serious harm did similar work but flipped the burden: triviality made the defendant disprove harm, serious harm makes the plaintiff prove it. See the serious harm threshold, concerns notices and defamation defences in Australia for the section-by-section detail.

What Stage 2 Added, and Why South Australia Is Different

Stage 2 addressed a gap Stage 1 left open: liability for platforms and intermediaries that carry other people's defamatory content rather than authoring it themselves. Where adopted, Stage 2 exempts intermediaries that merely cache, relay or store content with no active role, exempts search engines over organic results, and gives an intermediary a defence where it operates an accessible complaints process and takes access-prevention steps within seven days of a valid complaint. South Australia is the exception that must not be flattened into "SA adopted Stage 2." SA took a court's power to order a non-party intermediary to prevent access once an injunction issues, and it extended absolute privilege to reports made to police, but it declined the intermediary exemptions and the complaints-based defence that every other reforming jurisdiction adopted. A digital intermediary operating in SA has no statutory safe harbour and remains exposed to ordinary publisher liability at common law. See online defamation in Australia and defamation law in South Australia for the detail.

Damages: The Cap Rose to $520,000 on 1 July 2026

Every jurisdiction caps damages for non-economic loss, and every jurisdiction's cap reached $520,000 from 1 July 2026, verified against each jurisdiction's own government gazette rather than assumed to move together. The cap indexes annually against average weekly earnings and is rounded to the nearest $500; it started at $250,000 in 2005. It is a ceiling, not a scale, reserved for the most serious case, with courts assessing lower awards below it on the facts. Aggravated damages are awarded separately and sit outside the cap entirely, a point frequently misreported. See defamation damages in Australia for the jurisdiction-by-jurisdiction section numbers and the full mechanics.

The Cases Shaping Online Defamation

Three High Court decisions do most of the work in this area. Fairfax Media Publications Pty Ltd v Voller [2021] HCA 27 held that a media company was a publisher of third-party comments left on its own public Facebook page, because creating the page and posting content facilitated and encouraged those comments. Google LLC v Defteros [2022] HCA 27 held the opposite for a search engine merely displaying an organic hyperlink and snippet: that alone did not make Google a publisher of the linked article. Lange v Australian Broadcasting Corporation (1997) 189 CLR 520 established that the constitutionally implied freedom of political communication is not itself a defence, but modified the common law defence of qualified privilege to extend to political and government matters published to the public where the publisher acted reasonably. See online defamation in Australia and defamation defences in Australia for how each case is applied.

Who Can Sue: The Excluded Corporation Rule

A corporation generally has no cause of action for defamation in Australia. The exception is an "excluded corporation": either a not-for-profit whose objects do not include financial gain for its members, or a corporation with fewer than ten employees that is not an associated entity of another corporation and not a public body, with part-time staff counted pro rata. This rule applies in the same form in every jurisdiction covered on this hub.

This hub provides general legal information about defamation law across Australia, verified 20 July 2026. It is not legal advice about your own situation, and nothing on this page or elsewhere in this cluster should be read as an assessment of whether any particular publication is or is not defamatory. For advice on your circumstances, consult a legal practitioner admitted in the relevant Australian state or territory.

Explore each topic in detail: the serious harm threshold, concerns notices, defamation defences, defamation damages, online defamation, and defamation time limits in Australia. State pages: Western Australia, Northern Territory, South Australia and Tasmania.