Ms White, who led the Tasmanian party to three election losses, on Thursday announced her resignation from parliament effective immediately.
"The time has come for me to step aside and focus my energy on the upcoming federal election campaign, where I hope to continue my service to our community of Lyons in the Australian parliament," she said in a statement.
"It is with great excitement that I now dedicate myself to the task of winning the support of my community to represent them in the federal parliament."
Tasmanian Labor leader Dean Winter praised Ms White's enormous contribution to state politics over the past 15 years.
"The qualities that made Rebecca exceptionally effective in state parliament will continue to serve her community as she officially starts her campaign for the federal seat of Lyons," he said.
"We will miss her, but our loss is Prime Minister Albanese's gain."
Ms White said she timed her resignation to allow the electoral commission to conduct a re-count and enable the next member for the seat to join the parliament for the first sitting week in March.
A mother of two, the former Labor leader was first elected in 2010 in the electorate of Lyons after graduating from university six years earlier with a commerce and arts degree.
She took on the role of opposition leader after former leader Bryan Green resigned in 2017.
Ms White stepped down as the party's leader after the party's 2021 state election defeat, but was reinstated three weeks later when her successor David O'Byrne quit over sexual harassment complaints from a decade earlier.
She led the party to a third loss in 2024 before stepping down as leader but remaining in the parliament.
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