How serious is “serious harm” in Australian defamation law?

Since the first stage of reforms to the Uniform Defamation Acts, a defamation claim in Australia cannot succeed unless the claimant satisfies a threshold "serious harm" element (Western Australia being the exception).

The legislation, however, does not define what "serious harm" actually means.

Against a backdrop of several recent decisions, the Full Court of the Federal Court of Australia's judgment in Latham v Greenwich 2026 FCAFC 82 (Latham) has gone some way to settling how courts will approach the serious harm requirement.

Latham was an appeal from a first-instance decision in which Mark Latham, a member of the NSW Legislative Council, was found to have defamed Alex Greenwich, a member of the NSW Legislative Assembly, by way of a post on Twitter (now X).

The principles set out in Latham

In Latham, the Full Court identified the following principles governing the serious harm threshold:

• "Serious harm" is an "open textured phrase" that must be construed according to modern principles of statutory interpretation — that is, by reference to the provision's text, context and purpose.
• The threshold is not simply the inverse of the former triviality defence. It is not met by establishing some harm; rather, it calls for "harm of a higher order".
• Even so, the threshold was never intended to be an "especially high" one demanding extensive evidence from an applicant.
• Serious harm may be established by direct evidence, but in many cases it will be a matter of drawing inferences from the surrounding circumstances. Relevant considerations include (but are not limited to):
  • the gravity of the imputations;
  • the extent of publication and any likely "grapevine effect";
  • whether an apology was made promptly and how widely it was circulated;
  • the publisher's reputation and the medium used; and
  • the applicant's pre-existing reputation.

The "spectrum" approach — not adopted

The Full Court declined to follow the "spectrum" analysis adopted by the NSW Court of Appeal in Rader v Haines 2022 NSWCA 198 (Brereton JA, with whom Macfarlan JA agreed) (Radar).

Rader concerned section 1 of the Defamation Act 2013 (UK), the English provision that requires serious harm before a publication is treated as defamatory and which served as inspiration for the Australian provision. Brereton JA considered it useful to explain "serious" by locating it on a scale of severity, placing "serious" harm above "substantial" but below "grave". His Honour also emphasised that harm may be substantial without crossing the line into serious harm.

In Latham, Wheelahan and Abraham JJ (Colvin J agreeing on this point) observed that although the Australian provision was "inspired" by its English counterpart, it was not "modelled on it", so Rader carries "no special precedential status". The better course, in their view, is to give "serious harm" its "plain and ordinary" meaning, rather than interpreting it "by reference to judicial language used to explain a different provision enacted in a different jurisdiction with a different legislative context".

The same distinction between the English and Australian provisions had been drawn by Campbell J of the Supreme Court of New South Wales in Moore v Martin 2026 NSWSC 493, handed down shortly before Latham.

The "plain and ordinary meaning" approach — preferred

As noted, Latham holds that "serious harm" is to be given its "plain and ordinary meaning". A line of earlier authority adopts the same position and is critical of the spectrum approach. For example:

• In a separate judgment in Rader, Basten AJA cautioned against "seeking synonyms" and placing "serious harm" on a scale "between other terms of equal imprecision" (though he otherwise agreed with Brereton JA).
• In Selkirk v Hocking (No 2) 2023 FCA 1085, O'Callaghan J endorsed Basten AJA's reservation, warning that courts "risk leading themselves into error by positing alternative taxonomies to ordinary and well-understood English phrases used in legislation".
• In Peros v Nationwide News Pty Ltd (No 3) 2024 QSC 192, Applegarth J likewise agreed with Basten AJA.
• Wheelahan J — one of the bench in Latham — had earlier warned in Mond v The Age Company Pty Ltd 2025 FCA 442 of the "dangers of substituting judicial language for the text of legislation".
• Soon after Mond, the Queensland Court of Appeal in MG v PG 2025 QCA 99 held that courts "need not advance any alternative nomenclatures when construing this term" (Flanagan JA, with whom Brown and Davis JJA agreed).

A contrasting position emerged earlier this year in Supaphien v Chaiyabarn 2026 ACTCA 5. There, the appellant argued that the primary judge's reliance on the spectrum approach — in particular, the conclusion that serious harm meant more than substantial harm — amounted to judicial error. The ACT Court of Appeal dismissed the appeal. McCallum CJ and Loukas-Karlsson J held that the use of the spectrum approach was not "an error of principle or…the application of a wrong test" but simply "a choice between permissible approaches to the task of statutory construction". That said, their Honours clearly favoured Basten AJA's approach, as did McWilliam J, who in a separate judgment agreed with MG (while also dismissing the appeal, on the basis that serious harm had not in any event been established).

The Full Court in Latham took the view that the Queensland Court of Appeal's reasoning in MG was correct and to be preferred over Supaphien. The upshot is that the spectrum approach to serious harm now looks set to become little more than a historical footnote in the evolution of post-reform defamation law.

Key takeaways:

• In deciding whether a defamatory publication has caused, or is likely to cause, serious harm to the aggrieved person's reputation, a court must weigh a range of matters arising from the circumstances of that particular publication.
• The phrase "serious harm" is to be given its "plain and ordinary meaning", read also in light of the context and purpose of the provision.
• While direct evidence may help establish serious harm, in many cases it will instead be a matter of drawing inferences from all the surrounding circumstances of the publication.

Winterkorn Legal Group advises clients throughout Australia on defamation, reputation management and related commercial disputes. To discuss your situation, contact us at 1300 660 884 or make an enquiry through our website.