The disgraced former Liberal staffer had sued Network Ten and journalist Lisa Wilkinson for defamation over an interview with Brittany Higgins on The Project in 2021 in which she claimed she had been raped.
Justice Michael Lee found in April 2024 that Lehrmann had, on the balance of probabilities, raped Ms Higgins in Parliament House in 2019 after a night out.
The finding was upheld by the full court of the Federal Court on Wednesday.
Ms Higgins expressed her relief at the decision in a statement on social media.
"Finally, it feels like I can breathe again," she posted on Instagram, thanking the court for its decision.
"While on the face of it this was a defamation case against a media outlet, in reality this was once again a rape trial.
"I cannot begin to tell you how retraumatising it is to have your rapist weaponise the legal system against you for daring to speak out.
"Sadly, this isn't uncommon. It's a legal tactic that is being increasingly used around the world by perpetrators in a bid to sue victim-survivors into silence as a direct response to the #MeToo movement."
Lehrmann has always denied he sexually assaulted Ms Higgins, and a criminal case against him in 2022 was abandoned without any findings.
He did not appear in court on Wednesday and was represented by lawyer Zali Burrows, who said he was "overwhelmed" by the decision and was seeking advice on applying for special leave to contest the decision in the High Court.
Lehrmann was directed to pay $2 million in damages after his initial defamation loss, and he must now also foot the bill for the legal costs of his opponents during his unsuccessful appeal.
The 30-year-old had another court matter on Thursday, this time in Hobart, over a November 2024 incident where he absconded with a Toyota Prado.
The matter was heard before magistrate Robert Webster in a "contest mention" hearing, with most content suppressed.
Prosecutor Bunewat Keo advised the court that a previous charge of car theft had been downgraded to driving without consent.
While Ms Burrows attended court, Mr Lehrmann was not sighted - contrary to an order last month from Mr Webster that he must appear or risk arrest.
Prior to the hearing, Ms Burrows told waiting journalists that her client was "not in a good way", asking for compassionate coverage.
The matter continues before the Hobart Magistrates Court.
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