Environmental lawyer Steph Hodgins-May will become the next Greens senator for Victoria after the retirement of Janet Rice.
Ms Hodgins-May was previously a candidate for the Victorian seat of Macnamara, held by Labor's Josh Burns, and acted as Greenpeace's head of the Pacific.
She received a 5.5 per cent swing towards her in the party's primary vote at the federal election in 2022.
Fighting for climate action, rent freezes and cost of living relief will be priorities, she said.
"People are struggling to get by with the price of fundamental things like food and rent forcing impossible decisions," she said.
"I'm a mum, the partner of a refugee and the daughter of a farmer and a teacher - the combined cost of living and housing crises hit close to home and I'm ready to fight for fairness."
Greens leader Adam Bandt welcomed Ms Hodgins-May and thanked the outgoing Senator Rice.
"Steph is a courageous champion and I can't wait to have Steph as part of the formidable team," he said.
The Greens are targeting the Victorian seats of Macnamara, Wills, Higgins and Cooper.
Senator Rice will leave the Senate next year.
Australian Associated Press