Australia’s defamation laws have produced some of the most high-profile court cases in the country’s history. Here’s how defamation works, what defences exist, and how the rules have changed.
Defamation law protects people’s reputations from false and damaging statements. In Australia, it can apply to almost any publication: newspaper and TV stories, books, social media posts, online reviews and even emails.
Australia has long been considered one of the easiest places in the world to sue for defamation, and has been described as the “defamation capital of the world”.
What has to be proved
To succeed in a defamation case, a person generally needs to show that material was published to at least one other person, that it identified them, and that it conveyed a defamatory meaning, something likely to make others think less of them.
Since reforms introduced in most states in 2021, they must also show the publication caused, or is likely to cause, serious harm to their reputation. For companies, it must cause serious financial loss. The change was designed to stop minor claims clogging the courts.
Companies with 10 or more employees generally can’t sue for defamation, although their executives can.
The defences
The most important defence is truth, known as justification. If the publisher can prove what it published was substantially true, the claim fails.
Honest opinion protects genuine opinions based on proper material, on matters of public interest.
In 2021, a new public interest defence was introduced, protecting publications on matters of public interest where the publisher reasonably believed publishing was in the public interest. It was designed to give greater protection to responsible journalism.
There are also defences for things such as fair reports of court and parliamentary proceedings.
High-profile cases
Defamation cases have produced some of Australia’s biggest legal stories.
In 2023, former SAS soldier Ben Roberts-Smith lost his defamation case against Nine newspapers, after a judge found the newspapers had proved the substantial truth of allegations that he committed war crimes, including murder. His appeal was dismissed in 2025.
In 2024, Bruce Lehrmann lost his defamation case against Network Ten over its reporting of Brittany Higgins’ rape allegation, after a judge found, on the balance of probabilities, that he had raped her.
Online and social media
Defamation applies to social media posts and comments, and courts have held that people who post on social media can be responsible for what they write. Reforms introduced from 2024 clarified the liability of online platforms and search engines.
The debate
Supporters of strong defamation laws say they protect people from damaging lies. Critics argue they can be used by wealthy and powerful people to silence journalists and critics, and that the cost of defending a case can deter publishers from reporting important stories.
