A candidate backed by billionaire Clive Palmer candidate will join the Senate crossbench following the declaration of the vote count in Victoria and Western Australia.
Labor picking up a third seat in WA took its numbers to 26, requiring one minor party or independent vote on top of the Greens' 12 votes to pass legislation in the upper house with 39 votes required.
Ralph Babet took the sixth spot for the United Australia Party in Victoria from Liberal Greg Mirabella, who was only sworn into the Senate in February after filling a casual vacancy left by former president Scott Ryan.
Mr Palmer spent upwards of $100 million on his national election campaign, dominating the airwaves and installing bright yellow-themed billboards around the country.
The Victorian Senate seat was the mining magnate's sole electoral success.
Mr Babet, also known as Deej Babet, worked as a Melbourne real estate agent before taking a tilt at the upper house.
He ran on an anti-big government platform, criticising Victoria's lockdowns and attacking the media for being alarmist on his social media page.
He also shared posts purporting international organisations like the World Economic Forum and "global elites" were cracking down on free speech and had "toyed with ideas of global surveillance on a level not even conceived by Orwell".
"Bend the knee, peasants!" Mr Babet wrote on his Facebook page alongside the WEF logo and a full readout of the article.
In another post, Mr Babet wrote: "I would like to congratulate the new prime minister of Australia on an excellent campaign. Well done (WEF chairman) Klauss Schwab."
Mr Palmer says his new senator will ensure hardworking Australians are represented in the Senate.
"The United Australia Party is committed to holding Labor and the Liberals accountable for their actions and adding positively to the national debate for a better democracy for all,'' the UAP founder said.
Mr Palmer said the UAP would field candidates in all Victorian state seats at November's election.
Mr Mirabella says he is deeply disappointed he didn't have the opportunity to prosecute issues such as self-reliance, energy, manufacturing and security which he raised in his maiden speeech.
"The outcome of the federal campaign poses many questions for the Liberal Party," he said in a statement on Monday.
"As an organisation we must frankly and honestly reflect on how we can promote our values to a broad nationwide constituency."
The Liberals' Sarah Henderson, the Nationals' Bridget McKenzie, Labor's Linda White and Jana Stewart, and the Greens' Lidia Thorpe were also elected in Victoria.
Both Labor candidates will replace outgoing members.
The Australian Electoral Commission has also declared the NSW senators, with the Greens taking a seat from Labor.
But Labor made up a seat in WA at the expense of the Liberals, with Afghan refugee Fatima Payman elected to the Senate.
The Liberals' Marise Payne and Jim Molan, and Labor's Deb O'Neill and Jenny McAllister were re-elected in NSW, while the Nationals' Ross Cadell was elected on a joint coalition ticket, and the Greens' David Shoebridge was promoted from NSW parliament.
In WA, the Liberal's Michaelia Cash and Dean Smith, Labor's Sue Lines and Glenn Sterle and the Greens' Dorinda Cox were all re-elected.
The Australian Electoral Commission also declared nine House of Representative seats on Monday, leaving only 22 of the 151 federal electorates to be formalised.
Australian Associated Press
