Larissa Waters promises to push for stronger climate action and “politics with heart” after being chosen to lead the federal Greens.
The senator triumphed over South Australian Sarah Hanson-Young and Mehreen Faruqi from NSW, who will stay on as deputy.
Senator Waters ran for the leadership unopposed after being selected through consensus.
“I am just so thrilled to have had the support of my colleagues to be the leader of the Australian Greens,” she told reporters on Thursday.
“We need a parliament that actually delivers for people and has the courage and the boldness and the heart.
“So I’m calling today for a progressive parliament and politics with heart.”
She is the first person from Queensland to be appointed leader.
The Greens lost three lower house seats at the election and failed to pick up any extras.
However, they are confident of wielding influence in the Senate, where the party holds the balance of power.

Walking out of the meeting arm-in-arm with her leadership team, Senator Waters called on the Albanese government to engage with the minor party to improve the lives of Australians.
“People elected us to get shit done,” she said.
Her second-in-command promised the Greens would use their leverage in the upper house to “demand more, not less”.
“To the right wing media, to the billionaires, to the big corporations and to the Albanese government … we are not going to take a step backwards on action, on climate, on the environment, on housing and for justice,” Senator Faruqi said.
Labor has at least 28 seats in the Senate and with the support of the Greens has the numbers to get legislation through the upper house.

Senator Hanson-Young will keep her role as the Greens’ manager of business, while Tasmanian Nick McKim will be party whip.
Adam Bandt, who had led the Greens since 2020, lost his seat of Melbourne to Labor at the May 3 poll.
The shock defeat ended Mr Bandt’s 15-year career in federal parliament.
Senator Waters said her former leader was desperately missed and would be welcomed back into the parliamentary party with open arms one day.
“I’m a different person to Adam. I take a different approach … but I lead a really strong team,” she said.
“We will be firm but constructive under this government and any future government.”
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