Jacob Hersant, 25, performed the gesture outside a Melbourne court in October 2023 after avoiding being locked up for violent disorder.
At the same time, he praised Adolf Hitler and stated: “Australia for the white man.”
The salute had been made illegal by state parliament days before and has since been outlawed across Australia.
Hersant was convicted last month and had been on bail until sentencing.
He faced a maximum 12-month jail term and a A$24,000 (£12,300) fine but received a single month in prison.
“If there was physical violence, then I would have imposed a sentence close to the maximum penalty,” said magistrate Brett Sonnet.
He said his words were “clearly racist and seek to promote white supremacy in Australia”.
The court heard Hersant was part of the National Socialist Network, which promoted white supremacy, deporting immigrants and far-right actors.
However, the neo-Nazi was in custody for just an hour before his lawyer appealed and again won him bail, arguing he should not be jailed for a non-violent act.
The 25-year-old also told reporters on his way into court: “We’re going to argue that the law is constitutionally invalid and it’s emotional and it’s anti-white.
“It’s my political view and I think it’s a good fight for us to have an argument in court saying these laws are invalid.”
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Three other men were convicted in June of giving the infamous straight-arm salute at a football game in Sydney.
Another trio were convicted last month of doing it outside the Sydney Jewish Museum. However, they all received a fine and were not jailed.
Dvir Abramovich, chair of the Anti-Defamation Commission and a campaigner against antisemitism, said Hersant’s prison sentence was a reminder Australia shows “no mercy to those who bring symbols of terror to our streets”.
“This isn’t just a sentence – it’s a national roar that symbols of Nazism have no place on our soil,” he said.
