Australia Defamation Laws: 2021 Reforms & How to Sue

Australia governs defamation through near-identical state and territory statutes, each titled the Defamation Act 2005, built on the nationally agreed Model Defamation Provisions. Since the 2021 reforms a person must now prove the publication caused or is likely to cause serious harm to reputation before a court will hear the claim (Defamation Act 2005 (NSW) s 10A).

For an overview of how other countries handle reputation claims, see our world defamation laws hub.

How defamation law is structured across Australia

Defamation in Australia is primarily a state and territory matter, not a federal one. Rather than one Commonwealth statute, each of the eight jurisdictions enacted its own Defamation Act 2005 reflecting the agreed Model Defamation Provisions, supplemented by the surviving common law (the Acts state that they do not displace the general law except where they are inconsistent with it). Because the texts are mirror legislation, section numbers and wording line up closely from state to state, which is why practitioners and courts routinely cite the New South Wales Act as a reference point (Defamation Act 2005 (NSW)). The Acts apply to natural persons and to limited categories of corporation: a company generally cannot sue unless it is a not-for-profit or employs fewer than ten people (s 9). The result is a single national framework administered through state and territory Supreme and District Courts.

The 2021 Stage 1 reforms

The most significant change in a generation arrived with the Stage 1 amendments, which reshaped who can sue and when. The reforms introduced a serious-harm element requiring the plaintiff to show the publication "caused, or is likely to cause, serious harm" to reputation (s 10A); a single-publication rule so the limitation clock runs from first publication rather than each download (s 14C); and a standalone public-interest defence modelled on UK law (s 29A). They also made a concerns notice a mandatory precondition to suing (ss 12A and 12B) and abolished the old triviality defence. Most jurisdictions, including New South Wales, Victoria, Queensland, South Australia, the Australian Capital Territory and Tasmania, commenced these provisions on 1 July 2021, though Tasmania's actual commencement date was 12 November 2021 (the date its Defamation Amendment Act 2021 received Royal Assent), roughly four months later than the others, a detail several secondary sources get wrong.

Watch out: Western Australia is the one jurisdiction that has adopted neither reform package; the pre-2021 rules continue there, so there is no statutory serious-harm threshold, no s 29A-style public-interest defence, and no mandatory concerns-notice gateway. The Northern Territory looked like a second holdout for years, but it is not any longer: the Defamation Legislation Amendment Act 2025 (NT) commenced on 11 August 2025 and brought the Territory's Defamation Act 2006 into line with the rest of the country in a single step, adding a serious-harm threshold, the newer defences, mandatory pre-litigation steps, and digital-intermediary liability rules all together, rather than adopting Stage 1 and Stage 2 years apart the way most other jurisdictions did. In the jurisdictions that adopted Stage 1 earlier, a separate Stage 2 package addressing digital intermediaries began commencing from 1 July 2024.

Libel, slander and the elements of a claim

Australia abolished the historical split between libel (written) and slander (spoken) defamation. Section 7 of each Act provides that the distinction at general law is abolished and that defamatory matter of any kind is actionable without proof of special damage. To succeed, a plaintiff broadly must establish that the matter was published to at least one third party, that it identifies the plaintiff, that it carries a defamatory meaning (an imputation that would lower the person in the estimation of ordinary reasonable members of the community), and, since 2021, that the publication caused or is likely to cause serious harm (s 10A). The harm element is now decided as a question of fact and can be determined before trial, which has given defendants an earlier exit point in weaker cases. Truth is not part of the plaintiff's case; it falls to the defendant to raise as a defence.

The defences

The statutory defences sit alongside surviving common-law defences, and a defendant may plead several at once. The core statutory defences are justification, where the defendant proves the imputations are substantially true (s 25); contextual truth, where other substantially true imputations mean the remaining ones do no further harm (s 26); honest opinion, protecting opinion (not fact) on a matter of public interest based on proper material (s 31); absolute privilege, covering parliamentary and court proceedings (s 27); qualified privilege, where the recipient has an interest in the information and the publisher acts reasonably (s 30); and the publication of public documents and fair-report defences. The headline addition from 2021 is the public-interest defence (s 29A), available where the matter concerns an issue of public interest and the defendant reasonably believed publishing it was in the public interest.

The limitation period and how to sue

Defamation has a short window. The limitation period is one year from the date of publication (s 14B), which under the single-publication rule generally runs from first publication of substantially the same matter. A court may extend the period to a maximum of three years from publication where it is satisfied it was not reasonable for the plaintiff to have commenced within the year (s 56A). Before suing, the plaintiff must serve a concerns notice on the publisher specifying the matter and the defamatory imputations, then wait out the applicable period (commonly 28 days) during which the publisher may make an offer to make amends (ss 12A, 12B and 14). Proceedings are then filed in a Supreme or District Court of the relevant state or territory.

Watch out: Serving a valid concerns notice and observing the waiting period is a precondition to commencing proceedings in the jurisdictions that adopted the 2021 reforms. Skipping it can derail an otherwise good claim.

Remedies and the damages cap

The usual remedies are damages and, in some cases, injunctions and corrections. Damages for non-economic loss (injury to reputation and hurt to feelings) are capped, and the cap is indexed and re-declared by each jurisdiction on or before 1 July each year, though the section number differs by jurisdiction: s 35 in New South Wales, Victoria, Queensland, Tasmania and Western Australia, s 33 in South Australia, s 32 under the Northern Territory's Defamation Act 2006, and s 139F of the ACT's Civil Law (Wrongs) Act 2002, which has no standalone Defamation Act at all. The capped maximum is reserved for the most serious cases. New South Wales's Attorney-General gazetted the cap at A$520,000 from 1 July 2026, up from A$478,500 in 2024-25, and South Australia independently confirms the same A$520,000 figure from the same date under its own s 33(3), after having reached A$500,000 from 1 July 2025; readers should confirm the figure gazetted in the relevant jurisdiction for the relevant year rather than relying on an earlier snapshot. There is no statutory cap on damages for proven economic loss, and courts may award aggravated damages separately where the defendant's conduct warrants it.

Online and social-media defamation

The internet has driven much of Australia's recent defamation litigation, and two High Court decisions frame the law. In Fairfax Media Publications Pty Ltd v Voller [2021] HCA 27, the High Court held that media companies operating public Facebook pages were publishers of defamatory third-party comments posted under their stories, because they facilitated and encouraged those comments. The decision underscored that running a comment-enabled page can expose the operator to liability for what others write. In Google LLC v Defteros [2022] HCA 27, a majority held that Google, by returning a search result with a hyperlink to a third-party article, was not the publisher of that article; providing a reference or hyperlink was treated differently from publishing the underlying matter. Together the cases mark out where responsibility falls online, and the Stage 2 reforms further address the position of internet intermediaries.

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This guide is part of our Australia law guides.

Frequently Asked Questions

Is there one national defamation law in Australia?

No. Each state and territory has its own Defamation Act 2005, but they all enact the uniform Model Defamation Provisions, so the rules are nearly identical across the country. Courts and lawyers often cite the New South Wales Act as the reference text.

What is the serious-harm element introduced in 2021?

Since the 2021 reforms, a plaintiff must show the publication caused, or is likely to cause, serious harm to their reputation (s 10A). The court can decide this as a question of fact, often before trial, which filters out weaker claims. Western Australia has not adopted this threshold. The Northern Territory had not either until the Defamation Legislation Amendment Act 2025 commenced on 11 August 2025, which introduced a serious-harm requirement there too, so Western Australia is now the only jurisdiction without one.

Did Australia abolish the difference between libel and slander?

Yes. Section 7 of each Act abolishes the distinction between libel and slander, and defamatory matter of any kind is actionable without proof of special damage. Spoken and written statements are treated the same way.

How long do I have to sue for defamation in Australia?

The limitation period is one year from publication (s 14B). A court may extend it to a maximum of three years from publication where it was not reasonable to sue within the year (s 56A). The single-publication rule means the clock generally runs from first publication.

What is a concerns notice and do I have to send one?

A concerns notice formally tells the publisher what was published and which imputations are defamatory. In jurisdictions that adopted the 2021 reforms it is a precondition to suing (ss 12A and 12B). After it is served, the publisher has a window to make an offer to make amends.

What is the public-interest defence?

Section 29A provides a defence where the matter concerns an issue of public interest and the defendant reasonably believed that publishing it was in the public interest. It was introduced in 2021 and modelled on a similar UK provision; it was not available in Western Australia or the Northern Territory at first, but the Northern Territory added an equivalent defence when the Defamation Legislation Amendment Act 2025 commenced on 11 August 2025. Western Australia remains the one jurisdiction without it.

How much can a court award in defamation damages?

Damages for non-economic loss are capped and indexed annually, though under different section numbers in different jurisdictions. New South Wales's cap reached A$520,000 from 1 July 2026 under a gazetted Attorney-General declaration, up from A$478,500 in 2024-25; South Australia and Queensland reached A$500,000 from 1 July 2025, and South Australia has since confirmed the same A$520,000 figure from 1 July 2026 under its own provision. Proven economic loss is not capped.

Can I be liable for comments other people post on my page?

Possibly. In Fairfax Media Publications Pty Ltd v Voller, the High Court held that operators of public Facebook pages were publishers of defamatory third-party comments. Whether liability attaches depends on the facts, and later Stage 2 reforms address the position of online intermediaries.

When did Tasmania's 2021 defamation reforms actually commence?

On 12 November 2021, when the Defamation Amendment Act 2021 (Tas) received Royal Assent, not 1 July 2021 as commonly reported. Tasmania was roughly four months behind New South Wales, Victoria, Queensland, South Australia and the ACT, which all commenced the same package of reforms on 1 July 2021.

Has the Northern Territory adopted Australia's defamation law reforms?

Yes, since 11 August 2025. The Defamation Legislation Amendment Act 2025 (NT) commenced that day and brought the Northern Territory's Defamation Act 2006 into line with most of the rest of the country, adding a serious-harm threshold, a mandatory pre-litigation step, the newer defences, and digital-intermediary liability rules all at once. Western Australia is now the only Australian jurisdiction that has not adopted these reforms.