The Dutch driver was challenging to get a spot in Sunday's race with Swiss F1 team Sauber, which replaced him as a driver late last year.
A Swiss arbitration court had already ruled Sauber could not deny van der Garde the right to drive for the team, and he sought to have the ruling enforced in Victoria state, where the Australian
Grand Prix is being staged. Justice Clyde Croft in the Supreme Court of Victoria decided Wednesday the Swiss ruling should be upheld.
Lawyers for the Sauber team appeared in the same court later Wednesday, and an appeal into the case will be heard Thursday morning.
Van der Garde said outside the court after the appeal was granted that he was still confident the court would rule in his favor.
"We'll see what comes out tomorrow and I'm still hopeful," he said.
Lawyers for the Sauber team had argued van der Garde was an unacceptable risk because he wasn't trained in the team's car and he did not have a custom seat, but van der Garde's lawyer Tom Clarke said his client was ready to work with the team to get a seat fitted before racing begins.
Sauber said in a statement "the outcome is unfortunately not as expected."
"We are disappointed with this decision and now need to take time to understand what it means and the impact it will have on the start of our season," Sauber team chief executive Monisha Kaltenborn said. "What we cannot do is jeopardize the safety of our team, or any other driver on the track, by having an unprepared driver in a car that has now been tailored to two other assigned drivers."
But van der Garde said outside court he was ready to race. Practice begins Friday for Sunday's race.
"I'm very fit and very strong. I'm looking forward to going back to the team, work hard and do our best for the weekend," he said.
"I'm the fittest ever. I've been training the last three months flat out."
Van der Garde also said that despite the legal battle, he was keen to work with Sauber again.
"I'm looking forward to going back to the team. I had a very good relationship, I still have a very good relationship, with the team," he said.
One of Sauber's current drivers, Marcus Ericsson or Felipe Nasr, would have to miss out for van der Garde to race in one of the two team cars.
"Well, I think it's up to them what they're going to do, and up to the team. It's not my thing," van der Garde said.
Van der Garde's lawyers lodged papers with the court last Friday. The driver, who was a reserve with Sauber last season, claimed to have a contract for a race seat this season, but the financially-troubled team appointed Ericsson and Nasr as its drivers for 2015, with both bringing lucrative sponsorship backing.
The 29-year-old van der Garde was also considered a leading candidate to be appointed as a race driver for the Manor team, which has just come under new ownership that will allow it to compete this season.
In documents lodged with the court, van der Garde said he was guaranteed a spot on this year's Sauber team on June 28, 2014, but team bosses reneged on the deal.
"In early November 2014, Mr. van der Garde was informed by Sauber's chief executive officer, Ms. Monisha Kaltenborn, that Sauber's two seats had been given to other drivers and that, as a consequence, Mr. van der Garde would not have a place as a driver in the team in 2015," the documents said.
Van der Garde originally took his case to the Arbitration Institution in Switzerland, which ordered Sauber to keep him on the team.
"The respondent (Sauber) was ordered to refrain from taking any action the effect of which would be to deprive Mr. van der Garde of his entitlement to participate in the 2015 Formula One season as one of Sauber's two nominated race drivers," the court documents said.
--Sapa-AP--
