The High Court of Australia on Wednesday unanimously upheld a ruling that the flag carrier had illegally laid off 1,700 workers at 10 airports across the country in November 2020 during the Covid-19 pandemic.
The country's highest court's ruling found that Qantas had breached Australia's Fair Work Act, which protects employee rights, reports the BBC.
The firings of baggage handlers and cleaners at the airports came at a time when the country had closed its borders and business was plummeting.
The court upheld that while Qantas had "sound commercial reasons" for the move, it had deprived workers of their rights to "engage in protected industrial action and... bargaining."
In a statement on Wednesday, Qantas apologised for the outsourcing the 1,700 jobs during the pandemic, but maintained it was a necessary financial measure during Covid.
"As we have said from the beginning, we deeply regret the personal impact the outsourcing decision had on all those affected and we sincerely apologise," the BBC quoted the statement as saying.
The court's ruling was welcomed by many.
The Transport Workers' Union said the finding was proof that "the entire Qantas board must be replaced by new directors including a worker representative".
The Union's national secretary Michael Kaine called the carrier's actions "the largest sacking found to be illegal" in Australian history and promised that workers would now seek compensation in court.
In recent weeks, the Australian flag carrier has faced public outrage after reaping record profits amid a series of scandals related to its actions throughout the pandemic, including allegations that it sold tickets on thousands of flights which were cancelled.
Amid mounting scandals, Alan Joyce, the long-time boss of Qantas, announced his early departure from the airline last week.
His successor Vanessa Hudson is the airline's first ever female leader.