Moira Deeming secured endorsement for top spot on the party's Victorian upper-house ticket for the Western Metropolitan Region after the other candidates withdrew from the running.
She previously dropped her candidacy after the party overlooked her for businessman and Indian community leader Dinesh Gourisetty, who garnered support from the party's moderate wing.
But he was forced to step aside after it was revealed he previously provided a character reference for a now-convicted child sex offender, triggering another preselection contest.
Mrs Deeming was the only eligible nominee remaining for the position.
On Sunday, she thanked everyone who had supported her - including state Liberal leader Jess Wilson - adding she looked forward to exposing "Labor's callous betrayal of hard-working families" ahead of the November election.
"When we win, I will work tirelessly to restore good governance to this great state of Victoria," she told AAP.
The outspoken politician has repeatedly made headlines since she was preselected by the party in 2022.
The former high school teacher was suspended from the Liberals after she attended a 2023 Let Women Speak rally that was gatecrashed by neo-Nazis.
She was later expelled from the Liberal party room after she threatened legal action against then-leader John Pesutto.
The former party boss was ultimately found to have defamed her by implying she was associated with neo-Nazis and ordered to pay $2.3 million in legal costs.
Mrs Deeming was welcomed back into the parliamentary party in December 2024 and named its representative for Melbourne's western suburbs.
She offered to defer some of Mr Pesutto's legal bill in exchange for conditions including her preselection, but the proposition was rebuffed.
The state Liberals' administrative committee agreed to lend Mr Pesutto $1.55 million to settle his debt to Mrs Deeming and avoid bankruptcy.
The loan prompted an ongoing legal challenge from a group of breakaway Liberals.
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