Defences to defamation: an overview

A person sued for defamation does not lose simply because the plaintiff proves that something defamatory was published. The law provides a set of defences, some created by the uniform defamation legislation and some inherited from the common law, and most contested cases are decided on them. This article maps the defences available in Australia as at October 2026, explains who has to prove what, and points to the detailed articles on each defence.

The map matters for both sides. A publisher who understands which defence fits can respond to a concerns notice with confidence, and a person who has been defamed can assess how likely it is that a defence will succeed before spending money on proceedings.

Who has to prove what

The plaintiff must prove the elements of the cause of action: that the matter was published, that it identified the plaintiff, that it carried defamatory imputations and, everywhere except Western Australia, that the publication caused or is likely to cause serious harm to the plaintiff’s reputation.¹ The plaintiff does not have to prove that the imputations are false.

Once those elements are made out, the burden shifts. Each statutory defence in Division 2 of Part 4 of the Defamation Act 2005 is expressed to apply “if the defendant proves” the matters it describes.² The defendant therefore carries the onus of establishing a defence on the balance of probabilities, and the more serious the imputation, the more cogent the evidence a court will expect before it is satisfied.³

Where a jury is used, the jury decides whether defamatory matter was published and whether any defence is established, and the judge decides damages.⁴ Juries are only available in some jurisdictions and only if a party elects one; serious harm is always decided by the judge.¹

The statutory defences

The uniform legislation sets out the following defences. The section numbers are those of the Defamation Act 2005 (NSW); Queensland, Victoria and Tasmania use the same numbers, South Australia’s are two lower (justification is s 23, for example), and the Australian Capital Territory and the Northern Territory use different numbering again.

Justification (s 25). It is a complete defence if the defendant proves that the defamatory imputations carried by the matter are substantially true.² Substantial truth means the imputation is true in substance; minor inaccuracies do not matter. See the article on justification.

Contextual truth (s 26). Where the defendant can prove that the matter also carried one or more other imputations that are substantially true, and the imputations that cannot be proved do no further harm to the plaintiff’s reputation because of the substantial truth of the proven ones, the defence succeeds.⁵ Since the 2021 amendments the defendant may rely on the plaintiff’s own imputations for this purpose. See the article on contextual truth.

Absolute privilege (s 27). Matter published in the course of proceedings of a parliamentary body, an Australian court or tribunal, or in the other circumstances listed in the section and Schedule 1, is protected regardless of the publisher’s motive.⁶ In every jurisdiction except Western Australia this now includes reports made to police officials acting in an official capacity. See the article on absolute privilege.

Publication of public documents (s 28). A fair copy, summary or extract of a public document, such as a judgment, a parliamentary report or a document open to public inspection under statute, is protected unless the plaintiff proves it was not published honestly for the information of the public or the advancement of education.⁷

Fair report of proceedings of public concern (s 29). A fair report of court proceedings, parliamentary proceedings, public inquiries, certain meetings and the other proceedings listed in s 29(4) and Schedule 3 is protected on the same honesty condition.⁸ See the article on public documents and fair reports.

Public interest (s 29A). Introduced in 2021, this defence applies where the matter concerns an issue of public interest and the defendant reasonably believed publication was in the public interest, assessed against all the circumstances including the factors listed in s 29A(3).⁹ See the article on the public interest defence.

Statutory qualified privilege (s 30). Where the recipient had an interest or apparent interest in receiving information on a subject, the matter was published in the course of giving that information, and the defendant’s conduct in publishing was reasonable, the defence applies.¹⁰ It is defeated by malice.

Scientific or academic peer review (s 30A). Also introduced in 2021, this protects matter published in a scientific or academic journal after independent review of its merit, together with assessments written by the reviewers and fair summaries or extracts.¹¹

Honest opinion (s 31). It is a defence that the matter was an expression of opinion rather than a statement of fact, the opinion related to a matter of public interest, and it was based on proper material.¹² There are three versions of the defence, covering the defendant’s own opinion, that of an employee or agent, and that of a third party commentator. See the article on honest opinion.

Digital intermediaries (s 31A). In the jurisdictions that have enacted the 2024 reforms, a digital intermediary that had an accessible complaints mechanism and took access prevention steps within seven days of a complaints notice has a defence in respect of third party content.¹³ See the article on innocent dissemination and digital intermediaries.

Innocent dissemination (s 32). A subordinate distributor, such as a bookseller, newsagent, librarian or a provider of a communications system with no editorial control, has a defence if it neither knew nor ought reasonably to have known that the matter was defamatory and its lack of knowledge was not due to negligence.¹⁴

Triviality (s 33). This defence, which applied where the circumstances of publication were such that the plaintiff was unlikely to sustain any harm, was repealed in 2021 everywhere except Western Australia, where it remains in force.¹⁵ In the reformed jurisdictions the serious harm element now does the work the triviality defence used to do.

The common law defences are preserved

Section 24 provides that the statutory defences are additional to any other defence or exclusion of liability available apart from the Act, including under the general law, and do not limit or abrogate those other defences.¹⁶ A defendant may plead a statutory defence and its common law counterpart in the alternative, and often does.

The most significant common law defences are the following.

Common law qualified privilege protects communications made where the publisher had a legal, social or moral duty or interest in making them and the recipient had a corresponding duty or interest in receiving them. Unlike s 30, it does not require the publisher to prove that its conduct was reasonable. It is the defence most often relied on for workplace complaints, references, reports to regulators and communications between people with a shared interest. It is defeated by malice.

The extended qualified privilege recognised in Lange v Australian Broadcasting Corporation protects communications to the general public about government and political matters where the publisher’s conduct was reasonable in the circumstances.¹⁷ It is grounded in the implied constitutional freedom of political communication.

Common law fair comment is the ancestor of the statutory honest opinion defence and remains available alongside it.

Consent, sometimes called leave and licence, applies where the plaintiff expressly or impliedly agreed to the publication of the matter complained of. The High Court recognised it as a defence distinct from privilege in Loveday v Sun Newspapers Ltd, although on the facts of that case the plaintiff had not consented in advance to the particular statement published.¹⁸ It is rarely established and is most often raised where the plaintiff invited or instigated the publication.

Which defences malice defeats

Malice, in the defamation sense, means publishing for an improper purpose rather than for the purpose the privilege exists to serve. Whether a publication was actuated by malice is decided according to the general law even where a statutory defence is in play.¹⁶

Malice does not defeat justification, contextual truth or absolute privilege. If the imputations are substantially true, or the occasion is one of absolute privilege, the defendant’s motive is irrelevant.

Statutory qualified privilege under s 30 is expressly defeated if the plaintiff proves that the publication was actuated by malice, and common law qualified privilege is defeated in the same way.¹⁰ The honest opinion defence is not defeated by malice as such but by proof that the opinion was not honestly held, or, in the case of the employee and commentator limbs, that the defendant lacked the required belief about the opinion holder’s honesty.¹² The public document, fair report and peer review defences are defeated if the plaintiff proves the matter was not published honestly for the information of the public or the advancement of education.⁷ The public interest defence has no express malice exception; the defendant’s state of mind is instead examined as part of the question whether the defendant reasonably believed publication was in the public interest.⁹

An offer to make amends as a defence

An offer to make amends is a procedural step rather than a defence in the usual sense, but it can end a case in the same way. If a publisher makes an offer to make amends as soon as reasonably practicable after being given a concerns notice (and in any event within the period the Act allows), was at any time ready and willing to carry it out, and the offer was reasonable in all the circumstances but was not accepted, it is a defence to the proceedings under s 18.¹⁹ In deciding whether the offer was reasonable the court must have regard to any correction or apology published before trial, including how prominently and how promptly it was published.¹⁹ The court may also take into account whether the complainant refused an offer limited to particular imputations, and any other relevant matter.¹⁹ Whether the defence is established is decided by the judge, not a jury.¹⁹

Because the defence depends on timing and on the content requirements in s 15, the period after a concerns notice is received is often the most important stage of a defamation dispute. See the articles on concerns notices and offers to make amends. An apology is not an admission of fault or liability, and evidence of an apology is not admissible to prove fault or liability.²⁰

Which defences fit which situations

The following pairings are common, although every case turns on its facts.

Online reviews of businesses and professionals usually raise honest opinion, together with justification for any factual statements in the review. A review that states the facts on which the reviewer’s view is based is much easier to defend than one that states conclusions alone.

Journalism and investigative reporting typically rely on justification, contextual truth, the public interest defence and, where the story reports court or parliamentary proceedings, the fair report defence. Statutory qualified privilege under s 30 has historically been difficult for mass media to establish because of the reasonableness requirement.

Workplace complaints, references and reports to regulators or police usually rely on common law qualified privilege, which depends on the reciprocal duty or interest between the parties and is lost if the complainant acted with malice. A report made directly to police now attracts absolute privilege in every jurisdiction except Western Australia.⁶

Political speech about the conduct of governments, parliaments and public officials may attract the Lange extended privilege, the public interest defence and honest opinion.¹⁷

Platforms, hosts and other intermediaries rely on innocent dissemination, the s 31A digital intermediary defence where enacted, and the exemptions for caching, conduit and storage services and search engines inserted by the 2024 reforms.

Differences between jurisdictions

The defences in this article are available in New South Wales, Victoria, Queensland, South Australia, Tasmania, the Australian Capital Territory and the Northern Territory, subject to differences in numbering. In South Australia the defences run from s 23 (justification) to s 30 (innocent dissemination), with the public interest defence at s 27A.²¹ In the Australian Capital Territory they are ss 135 to 139C of the Civil Law (Wrongs) Act 2002 (ACT), with the public interest defence at s 139AA and honest opinion at s 139B.²² In the Northern Territory they are ss 21 to 29 of the Defamation Act 2006 (NT), with the public interest defence at s 26A and honest opinion at s 28.²³

Western Australia’s Defamation Act 2005 is still in its original form.¹⁵ There is no serious harm element, and the triviality defence in s 33 remains. There is no public interest defence, no peer review defence and no digital intermediary defence. The contextual truth defence is in its original narrower wording. The offer to make amends provisions retain the original timing rule (as soon as practicable after the publisher becomes aware that the matter is or may be defamatory). Absolute privilege does not extend to reports to police. Western Australia is the only jurisdiction in which these differences arise, so a publication read in Perth may be defended differently from the same publication read in Brisbane.

South Australia has enacted the extension of absolute privilege to police reports and the orders against digital intermediaries, but not the s 31A digital intermediary defence.²¹

Getting advice

Which defence is realistic depends on what was published, to whom, in which jurisdiction, and what evidence exists to support it. The strength of the available defences also shapes how a concerns notice should be answered and whether an offer to make amends should be made. Advice taken early, before pleadings are settled, is usually cheaper and more useful than advice taken afterwards.