How serious is "serious harm" in Australian defamation law?

Since the first stage reform to the Uniform Defamation Acts, defamation claims in Australia cannot succeed without satisfying a threshold element of "serious harm" (except in Western Australia).

The legislation does not define the meaning of "serious harm".

Against the background of a string of other recent decisions, the recent judgment of Latham v Greenwich [2026] FCAFC 82 has provided more certainty into how courts will interpret serious harm.  

Latham was an appeal from a decision where Mark Latham, a member of the NSW Legislative Council, was found to have defamed Alex Greenwich, a member of the NSW Legislative Assembly, through a post he made on Twitter (now X).

Following consideration of existing case law, the Full Court of the Federal Court of Australia in Latham set out the following principles in relation to the serious harm threshold for defamation:

• serious harm is an "open textured phrase" to be interpreted in accordance with modern principles of statutory construction, including looking at the provision's text, context and purpose;

• the serious harm threshold is not a converse of the former triviality defence – it is not merely satisfied by proof of some harm and requires "harm of a higher order";

• nevertheless, the serious harm threshold was not intended to establish an "especially high threshold" requiring extensive evidence to be led by an applicant;

• proof of serious harm may be supported by direct evidence but can and often will depend on drawing inferences from all the circumstances, including but not limited to:

  • the gravity of the imputations;

  • the extent of publication and any likely "grapevine effect";

  • whether there was a prompt apology and how broadly that apology was published;

  • the reputation of the publisher and the medium of the publication; and

  • the applicant's existing reputation.

Spectrum approach ("place on a scale") – not followed

The Full Federal Court in Latham chose not to follow the "spectrum" approach from the NSW Court of Appeal decision of Rader v Haines [2022] NSWCA 198 (Justice Brereton, with whom Justice Macfarlan agreed).

The Rader proceeding concerned the application of the English law provision, section 1 of the Defamation Act 2013 (UK) (which requires serious harm for a publication to be defamatory), from which the Australian serious harm provision drew inspiration. In his judgment, Justice Brereton considered there was utility in giving some explanation of the meaning of "serious" by visualising where it sits on a scale of severity.

His Honour considered that “serious” harm sits above “substantial”, but below “grave”. His Honour also pointed out the importance of recognising that there can be harm which is substantial but does not reach the level of serious harm.

In Latham, Justices Wheelahan and Abraham (with whom Justice Colvin agreed on this issue) noted that while the Australian serious harm provision was "inspired" by the English law provision, it was not "modelled on it" and therefore Rader "does not have any special precedential status".

Instead, the serious harm provision should be interpreted using the "plain and ordinary" meaning of the word "serious", and "not by reference to judicial language used to explain a different provision enacted in a different jurisdiction with a different legislative context".

This distinction between the English and the Australian serious harm provisions was also noted by Justice Campbell of the Supreme Court of New South Wales in Moore v Martin [2026] NSWSC 493, decided shortly before Latham.

Direct application approach ("plain and ordinary meaning") – preferred approach

As noted, Latham says that the correct approach to interpreting "serious harm" is to adopt its "plain and ordinary meaning".  A number of earlier cases have also taken this approach and have criticised the spectrum approach. For example:

• In a separate judgment in Rader, Justice Basten warned of the risks of "seeking synonyms" and placing "serious harm" on a scale "between other terms of equal imprecision" (but agreed with Justice Brereton's judgment other than that reservation).

• Justice O'Callaghan, in Selkirk v Hocking (No 2) [2023] FCA 1085, agreed with Justice Basten's reservation, warning that courts "risk leading themselves into error by positing alternative taxonomies to ordinary and well‐understood English phrases used in legislation".

• Justice Applegarth, in Peros v Nationwide News Pty Ltd (No 3) [2024] QSC 192, agreed with Justice Basten's position.

• One of the bench in Latham, Justice Wheelahan, had previously warned in Mond v The Age Company Pty Ltd [2025] FCA 442 about the "dangers of substituting judicial language for the text of legislation".

• Shortly after Mond, in MG v PG [2025] QCA 99, the Queensland Court of Appeal ruled that courts "need not advance any alternative nomenclatures when construing this term" (per Justice Flanagan, with whom Justices Brown and Davis agreed).

On the other hand, earlier this year, in Supaphien v Chaiyabarn [2026] ACTCA 5, the appellant complained that the primary judge's use of the spectrum approach when interpreting what "serious harm" meant (in particular, concluding that it meant more than substantial harm) while assessing her defamation claim amounted to judicial error. The ACT Court of Appeal dismissed her appeal. Rather than being "an error of principle or…the application of a wrong test", Chief Justice McCallum and Justice Loukas-Karlsson held that the use of the spectrum approach was simply "a choice between permissible approaches to the task of statutory construction". That said, their Honours plainly preferred Justice Basten's approach, as did Justice McWilliam, who, in a separate judgment, agreed with what was said in MG (although her Honour also dismissed the appeal, considering serious harm had nevertheless not been established).

Latham considered that the Queensland Court of Appeal's approach in MG was correct and should be followed rather than Supaphien. Consequently, the spectrum approach to assessing serious harm now seems set to be a historical footnote in the evolution of post-first stage reformed defamation law.