Attwood Marshall Lawyers Commercial Litigation Special Counsel Jade Carlson discusses defamation law in Australia – including what you need to prove to bring a claim, and how the serious harm threshold introduced in 2021 has changed the legal landscape.
July 2026 marks five years since the serious harm threshold came into effect under Section 10A of the Defamation Act 2005, fundamentally changing what a plaintiff must establish before a defamation claim can proceed.
While the threshold has succeeded in reducing trivial claims, questions around causation and what constitutes sufficient evidence of serious harm remain contested. In a recent Law Society Journal article, practitioners reported that early conversations with clients now centre squarely on whether a serious harm argument can be made, and many matters that would previously have proceeded to court are resolved before they get there. It’s a change that we have noticed in our practice too.
Still, with 63.9 per cent of the world’s population using social media, and platforms like Instagram, Facebook, WhatsApp, and Messenger seeing billions of monthly active users, the volume of potentially defamatory material being published online every day is significant. Understanding where the law draws the line has never been more important.
Defining “defamation”
In its simplest form, defamation is the publication of material which harms a person’s reputation.
To succeed in a defamation claim, the aggrieved person (or plaintiff) must prove that:
- The material has been published to a third party;
- The material clearly identifies the aggrieved person;
- The material contains defamatory imputations about the aggrieved person that are untrue;
- The publication of the material has caused, or is likely to cause, serious harm to the aggrieved person’s reputation.
If these elements are proven and no defence applies, a court may award damages proportionate to the harm caused to the plaintiff’s reputation.
Understanding defamation
It is the effect of what is said (the imputations carried) that the court assesses, rather than the literal words used.
For example, John Doe engages Stephen Smith to undertake some plumbing work. Stephen Smith charges more than initially anticipated. John Doe leaves a Google review, stating “Stephen Smith is a lousy plumber and crook.” Stephen Smith might allege that the post carries imputations that he is incompetent, dishonest and a fraudster, which are untrue and therefore defamatory.
Material published online is generally treated the same as any other type of publication.
Some courts have also held that liking, reposting or sharing someone else’s content can be viewed as a republication of defamatory content – meaning you may be treated as having said it yourself.
Even if you did not intend to defame someone, you can still be held liable. If found to have defamed another person, whether intentionally or not, you may be ordered to pay:
- General damages (non-economic loss), with the maximum amount being increased in Queensland to $500,000 from 1 July 2025 for distress and hurt caused by the publication;
- Special damages (economic loss) for harm to a personal business reputation, and
- Aggravated damages, where the court considers the publisher acted in a reckless disregard for the harm caused.
The serious harm threshold
The serious harm threshold provision was introduced in 2021 to address concerns that defamation law was increasingly being used for trivial, spurious and vexatious claims, and that the costs of defending a defamation claim was becoming prohibitive for private individuals.
The NSW Supreme Court gave the threshold its first judicial consideration in Newman v Whittington [2022] NSWSC 249. Ms Newman alleged that Mr Whittington had posted 27 defamatory imputations about her online, predominantly on Facebook. The court confirmed that a plaintiff must produce concrete evidence of actual harm caused, or likely to be caused – assertion alone is not sufficient.
In Queensland, the Supreme Court considered the issue in Peros v Nationwide News Pty Ltd & Ors (No 3) [2024] QSC 192 (Peros v Nationwide News), finding that the plaintiff failed to prove the serious harm element. The court emphasised that section 10A abolishes the presumption of damage and requires proof that the publication itself caused or is likely to cause serious harm, with the assessment being qualitative rather than numerical.
The Supreme Court in Peros v Nationwide News identified a non-exhaustive list of factors for determining whether serious harm has been met:
- Gravity of the imputation: more serious allegations increase the likelihood of serious harm.
- Extent of publication: broad dissemination can support an inference of harm, but mass publication alone is not sufficient.
- Credibility of the publisher: credible, reliable sources are more likely to cause serious harm.
- Form and medium: a considered publication carries more potential for harm than a spontaneous social media post.
- Identity of the recipient: statements made to people who immediately disbelieve the material are less likely to cause serious harm.
- The plaintiff’s prior reputation: a plaintiff with a poor prior reputation will have difficulty proving the publication caused serious harm.
- Cause of harm: the plaintiff must isolate the damage caused by the specific publication, as the defendant is only responsible for their own publication.
- Proof of serious harm: actual harm must be proven – harm is no longer presumed.
Online reviews and social media pages
Given that up to 97 per cent of consumers read reviews before making a purchase, platforms such as Google, Tripadvisor, Yelp, and Facebook can have a material impact on a business’s reputation.
It is often following a negative review that defamation disputes arise.
Another area of defamation law concerns the liability of social media page administrators. A NSW Court held Fairfax Media Publications, Nationwide News Pty Ltd, and Australian News Channel Pty Ltd liable for comments made by members of the public on a news article they had shared on their Facebook page.
The person who featured in the story commenced defamation proceedings against the publishers, claiming that third-party comments conveyed defamation imputations about him and that the publishers were liable as publishers of those comments.
The court determined that a person who participates in and is instrumental in bringing about the publication of defamatory matter is potentially liable, regardless of whether others also participated in that publication.
Queensland has since enacted its own reforms in this area. The Defamation and Other Legislation Amendment Act 2025, which passed in December 2025, introduced a new defence for digital intermediaries – including platform administrators – provided they maintain a complaints process and take reasonable steps to remove defamatory content within seven days of receiving a complaint.
Read our full analysis of the Queensland reforms here.
Anyone running a business or managing online pages should have appropriate processes in place to monitor and moderate public comments.
Accused of defamation? What defence may be available to you
Each case turns on its own facts and merit, but generally, there are eight different defences to someone accused of defamation. These include:
- Justification: the statement made is substantially true.
- Contextual truth: the defendant proves that the matter carried one or more imputations that are substantially true, and any remaining defamatory imputations do not further harm the plaintiff’s reputation;
- Absolute privilege: the statement was made in a context where the law confers immunity, such as in Parliament or in court proceedings;
- Public document: the statement was taken from a public document, such as government document, and repeated accurately;
- Fair report: the statement was a fair report of an important public proceeding, such as a court case;
- Public interest: the defendant reasonably publication was in the interest of the public;
- Offer to make amends: the defendant made a valid offer to make under the Defamation Act that was not accepted by the plaintiff;
- Innocent dissemination: the defendant was not the primary distributor of the statement. Courts have increasingly scrutinised this defence, particularly in the context of social media platforms.
How a defamation lawyer can help
If you believe someone has published defamatory material about you, a defamation lawyer can advise you on whether your situation meets the serious harm threshold and help you prepare and serve a Concerns Notice on the publisher. The notice must be in writing, identify the defamatory imputations, and particularise the serious harm you have suffered.
If the material was published on Google or Facebook, your defamation lawyer may also seek to have it removed by notifying the platform directly.
If you are a recipient of a Concerns Notice, a defamation lawyer can advise you on whether to make an offer to make amends – which may include removing the material and contributing to the other party’s reasonable legal costs.
Where the harm to your reputation is minimal and the other party makes a reasonable offer, accepting it and avoiding the cost and stress of litigation may be the right outcome. Your defamation lawyer can advise you on your specific circumstances.
Attwood Marshall Lawyers – Experienced defamation lawyers helping to protect your reputation
Attwood Marshall Lawyers has a dedicated team of Commercial Litigation lawyers who practice exclusively in this complex area of law. We can assist with all defamation matters to help you protect your personal and professional reputation.
Contact our team to find out what action you can take by calling our Department Manager Georgia Trapp on direct line 07 5506 8278, email gtrapp@attwoodmarshall.com.au or free call 1800 621 071.
Our defamation lawyers are available for appointments at all our conveniently located offices at Robina Town Centre, Coolangatta, Southport, Kingscliff, Brisbane, Sydney, and Melbourne.
