The Greens have won the blue-ribbon Liberal seat of Ryan on the back of a massive swing to the party in inner-Brisbane, which has put them in a strong position to claim two more.
Greens candidate Elizabeth Watson-Brown has defeated one-term Liberal MP Julian Simmonds in the seat of Ryan in Brisbane's western suburbs.
The seat has been won by the Coalition at every general election since 1972.
Mr Simmonds's primary vote slipped below 40 per cent and the Greens will win the seat on preferences after securing a swing of more than 11 per cent.
The Greens' Max Chandler-Mather is ahead in Griffith and Stephen Bates is also in front in the seat of Brisbane.
Mr Chandler-Mather said the Greens' result in Brisbane was a "beacon of hope" for Australians "that you do not have to settle for the political status quo".
"I think we had a massive swing here because we spent 14 months knocking on over 90,000 doors, running community campaigns about everything from flight noise, helping clean up after the floods, we took a philosophy we needed to embed in our communities and in people's lives," he said.
Voters in each of these seats were badly affected by flooding in Brisbane in February and March.
With almost 33 per cent of ballots counted, the Greens were also likely to secure another senator from Queensland.
It remains unclear if Labor can form a majority government, the ALP is on track to finish ahead of the Coalition and likely to reach a minority government at a minimum.
Despite the Greens potentially claiming up to three seats in Queensland, the state remains an LNP stronghold.
The LNP won 23 seats out of 30 in the state in 2019, and while there has been a swing towards Labor in most seats, it was not enough for the party under Anthony Albanese to make up any ground.
Ms Watson-Brown will become the country's second Greens MP after Adam Bandt won the seat of Melbourne in 2010.
Mr Bandt, now the Greens leader, told the ABC the party had been targeting Brisbane's inner-city electorates ahead of the election.
"In Griffith, we've knocked on every door and had over 30,000 conversations with voters in that seat and that has been our strategy across those inner-city Brisbane seats," he told the ABC.
"I've spent time with my colleagues in Queensland and New South Wales to take a comprehensive approach that said we need to get out of coal and gas but do it in a way that supports workers and communities … that is important for people not just in those areas but also to those in the inner city as well, who are seeing we are making the transition, but doing it fairly.
"Those key elements, we have been campaigning strongly on those for three years within the Parliament and outside the Parliament and we are seeing the results of that."
Mr Bandt suggested recent extreme weather in the state played a role in the result.
"I think increasingly what we're seeing is that that cuts across all voting persuasions, it cuts across all demographics — people know it's happening."
Addressing his supporters on Saturday night, Mr Bandt congratulated Labor leader Anthony Albanese on his election victory, and said he wanted to work with the party.
He said the Greens had work to do "to ensure that we come to an understanding that means we can deliver stable, effective and progressive government in this country with a new prime minister".
Results 'disappointing' for Labor: Chalmers
Shadow Treasurer Jim Chalmers, the MP for Rankin in Logan, south of Brisbane, said it was a sign the Labor party perhaps needed to re-evaluate its climate change policies.
"That is something that we'll have to engage with," he told the ABC.
"Clearly that aspect of it is disappointing to us because we do have an ambitious, credible climate change policy which is all about cleaner and cheaper energy.
"We built a broad coalition for that policy and we would have liked to have picked up more climate-conscious voters in the city, so we'll have to work out why that hasn't been the case."
Defence Minister Peter Dutton secured re-election in the seat of Dickson, north of Brisbane, but acknowledged the Liberal Party had "suffered a terrible day".
"There are colleagues around the country, good people, who have potentially lost their seats," he said.
"There are still thousands and thousands of postal votes and pre-poll votes to count, so there's some hope in some of those seats."
The Member for Leichhardt, Warren Entsch, looks set to retain the Far North Queensland seat and enter his ninth term in government, despite Labor targeting the seat as a winnable one.
The LNP have so far retained two Senate seats in Queensland, with both James McGrath and Matt Canavan re-elected.
Murray Watt has cemented his seat for the ALP with Anthony Chisolm also looking likely.
Penny Allman-Payne is looking likely to win her seat for the Greens, while One Nation's Pauline Hanson is currently ahead.
