Moira Deeming (born 1983) is an Australian politician who is a Liberal Party member for the Western Metropolitan Region of the Victorian Legislative Council, the upper house of the Parliament of Victoria, since November 2022. She sat as an Independent Liberal from 2023 to 2024, having been expelled from and then readmitted to the parliamentary Liberal Party. She previously sat as a councillor for the Melton City Council representing the Watts Ward.

Deeming is well known for her views on transgender people. On 18 March 2023, Deeming spoke at an anti-trans rally, which she helped organise, outside of the Victorian Parliament. The rally was attended by neo-Nazi groups who repeatedly performed Nazi salutes from the steps of Parliament.

Following Deeming's participation in the rally, leader of the opposition John Pesutto announced that he would move to have her expelled from the parliamentary Liberal Party. On 27 March 2023, Deeming was suspended from the parliamentary Liberal Party for nine months. After repeated legal threats against Pesutto, she was indefinitely expelled from the parliamentary party room on 12 May 2023. In December 2024 the Federal Court ruled that Pesutto had defamed Deeming by suggesting that she associates with Nazis. Deeming was readmitted to the parliamentary Liberal Party on 27 December 2024.

Deeming was born in Timboon, Victoria. In her maiden speech in the Legislative Council Deeming said that she was "born and bred on the political left coming from a long line of union leaders, card-carrying Labor Party members, and Labor MPs". Her great-grandfather was John Joseph Holland, a Labor MP for over thirty-five years and a councillor for the City of Melbourne.

Deeming identifies as being Māori. She is a Presbyterian, although she attended the Catholic high school St. Francis Xavier College. Deeming has a Bachelor of International Relations from La Trobe University and a Post-Graduate Diploma of Education from the University of Melbourne. She previously worked as a teacher for over a decade.

Deeming stood as a candidate for the Liberal Party in the lower house for the seat of St Albans at the 2014 Victorian state election. She secured 26.9% of the vote, losing to the Labor Party's Natalie Suleyman. At the 2018 state election Deeming stood as a candidate for the Liberal Party for the upper house Western Metropolitan Region seat in the Victorian Legislative Council. She received 356 first preference votes (0.08%) and failed to gain a seat.

Deeming stood as a candidate for Watts Ward at the 2020 Melton local election on 24 October, receiving 21.49% of the primary vote and successfully securing the second allocation.

Following the 2022 Australian federal election, it was reported in The Age that on 26 March the Victorian Liberal Party's administrative committee voted for Deeming to run in the lower house seat of Gorton. Before she was able to be endorsed, a top party official relayed the view of, then Prime Minister of Australia, Scott Morrison's Office that "negative media coverage of Deeming's hard-line social views could distract" from Morrison's campaign. Subsequently, another vote was held and a different candidate was picked.

On 23 July 2022, Deeming was endorsed by the Liberal Party to contest the upper house Western Metropolitan Region seat in the Victorian Legislative Council to replace Bernie Finn at the Victorian state election. Deeming's preselection was considered controversial because she replaced the similarly right-wing Bernie Finn at the top of the Liberal ticket, following Finn's expulsion from the Liberal Party after making "inflammatory social media posts". Finn, who contested the election as a Democratic Labour Party candidate, was reported to be "delighted" at Deeming's preselection. Andrew Elsbury, a moderate Liberal Party member who held the seat from 2010 to 2014 quit the party in response to her preselection, describing it as the "final straw". Deeming was subsequently elected to the Legislative Council.

On 18 March 2023, Deeming spoke at an anti-trans rally, which she helped British anti-transgender rights activist Kellie-Jay Keen-Minshull organise in Melbourne. The rally was also attended by the neo-Nazi group National Socialist Network (NSN) and its leader Thomas Sewell. The neo-Nazis repeatedly engaged in Nazi salutes and carried far-right extremist banners (including one that compared transgender people to paedophiles), which sparked clashes with counter protesters who attended the rally. Deeming later said that she had noticed the neo-Nazi group, but said she was told there was "nothing [they] could do" about their presence, and that she "just got back to [the] rally". Deeming denied seeing the group perform salutes. She also said that she struggles to remember the anti-trans rally she helped organise.

In a public statement Liberal opposition leader John Pesutto described Deeming's position as "untenable" due to her "involvement in organising, promoting and participating in a rally with speakers and other organisers who themselves have been publicly associated with far right-wing extremist groups including neo-Nazi activists". Pesutto then moved to expel her from the party. MPs Brad Battin and Richard Riordan attempted to delay a vote on expelling her by a week, but failed, losing the vote 18 to 11. It was reported that Deeming was also supported by Chris Crewther, Matthew Guy, Bill Tilley, David Hodgett, and Ann-Marie Hermans.

After failing to delay a vote on Deeming's expulsion, Liberal MPs lobbied Pesutto for a less severe punishment over her role in the rally. Deeming subsequently accepted a nine-month suspension from the party instead of expulsion from the party. The compromise came after Deeming issued a private statement in the party room, condemning Keen-Minshull's previous use of a Barbie wearing a Nazi uniform on her social media as a "poor distasteful joke".

During Deeming's suspension from the parliamentary party, she threatened party leader Pesutto with legal action, but backed away after a fresh attempt was made to oust her from the party. This second effort, led by former party leader Matthew Guy, saw Deeming back away from her threat of legal action.

Deeming reportedly returned to threatening the Liberal Party leader again after sending a letter reiterating the threat of a defamation case. On 12 May 2023 Deeming was expelled from the parliamentary party room by 19 votes to 11. Despite her expulsion, Deeming has re-iterated that she would never quit or resign from the party. In an interview with Sky News Australia's Peta Credlin, Deeming stated that she had been "betrayed" by the party and "relentlessly hunted" out of the party room following the anti-trans rally. As a result of Deeming's expulsion, she currently sits as an Independent Liberal.

In December 2023, after months of attempted mediation failed, Deeming filled a civil complaint against Pesutto. Deeming stated that she had been falsely accused of being an associate of "neo-Nazi sympathisers and extremists". She said that she had been defamed by Pesutto in media releases, a press conference and broadcast interviews. Pesutto denied Deeming's claims, stating that he had never called her a "neo-Nazi, white supremacist or anything similar". Pesutto's statement of defence however alleged that Deeming had failed to distance herself from people who had associated with people from the far-right.

During a hearing of the case in September 2024, the court was played secretly recorded audio of a meeting between Deeming, Pesutto, and Pesutto's leadership team. The meeting was recorded by David Southwick, Pesutto's deputy and immediately followed the anti-trans rally. In the audio played, Deeming was lectured for her role in the rally and for having champagne afterwards with Kellie-Jay Keen-Minshull. Deeming's lawyer in court said that the meeting was a "pile-on" and that a decision had already been made to remove her from the party.

In December 2024 the Federal Court ruled that Pesutto had defamed Deeming. Pesutto was ordered to pay $300,000 in damages, with a hearing at a later date to determine costs. As a result of her win, Deeming stated that she expected to be able to return to the parliamentary party room. On 20 December 2024, the Liberal party room voted down a proposal to readmit Deeming to the party room. The vote was 14-14, with Pesutto's final vote defeating the motion 14-15 for-against. On 22 December Pesutto called a Liberal party room meeting for 15 January 2025 to discuss his motion to readmit Deeming, stating that an "absolute majority" now existed to do so. He apologised to Deeming for defaming her, but Deeming said that she learned about the apology from media. On 27 December there was another motion to spill the leadership and readmit Deeming which passed.

Deeming is well known for her anti-trans views. In her maiden speech before the Legislative Council, Deeming stated that she was against Victoria's Safe Schools program, transgender people accessing toilets corresponding to their gender, and the decriminalisation of sex work. Deeming has described Safe Schools as being created by "paedophilia apologists" and "sleazy". In 2020 she described the "watch and wait" approach for treating gender dysphoria as "highly successful, low risk"—in line with the Victorian Liberal Party's statement that while they oppose gay conversion therapy, the Andrews' government legislation "allows government interference in the relationships between medical professionals and patients," and "unfairly targets psychiatry and psychotherapy specifically". On 18 March 2023, Deeming spoke at an anti-trans rally, which was part of anti-transgender rights activist Kellie Jay Keen's speaking tour.

Deeming is anti-abortion, believes that laws legalising abortion need to be repealed, and believes that rape victims should reject abortions and turn to the church. She is against voluntary euthanasia. Deeming is against the COVID-19 vaccine mandates, and considers vaccine passports immoral and a form of segregation. As of September 2021 she said in an interview that she was unvaccinated, and that she'd be waiting and that she was reserving her judgement due to concerns. Deeming is against changing the date of Australia Day. She is a member of the conservative think-tank Institute of Public Affairs.