It was her second attempt at the seat, after contesting the 2025 Federal Election, where she mounted a strong challenge against former Farrer MP Sussan Ley.
Following Ms Ley’s resignation from politics earlier this year, Ms Milthorpe was the first to announce her candidacy for the seat.
Although her second campaign was unsuccessful, Ms Milthorpe said she was grateful to the people of Farrer for their support.
“Across our electorate, people have let me into their homes and businesses and spoken honestly about what isn’t working,” she said.
“Those conversations have had a clear theme: out here, we feel forgotten by the major parties.”
In a rare outcome, the front-runners of the by-election were not from the major parties, which Ms Milthorpe said signalled a shift in voter sentiment.
“The major parties were barely in the picture. I hope they take this as the warning it is,” she said.
“The political class feels totally disconnected from our everyday lives, and voters are more ready than ever to register their discontent at the ballot box.”
While competition between Ms Milthorpe and One Nation was intense, she congratulated the successful candidate and said the real test would now be delivery.
“The next two years will be a test for One Nation. Reflecting anger is the easy part. The hard part is doing something about it,” she said.
“The people of Farrer have placed their trust in One Nation. Their success is our success, and I wish them all the best in their efforts in Parliament.”
Ms Milthorpe also thanked her volunteers and supporters, acknowledging the “result will be difficult to process”.
However, she urged supporters to remain engaged despite the loss.
“We have turned one of the safest seats in the country into one that will likely be marginal for many elections to come. We have changed Farrer forever,” she said.
“Don’t let this energy dissipate. Keep having conversations with friends, family and colleagues. Keep hoping for a better future for our kids. And keep fighting. I will be there fighting alongside you.”