2004 in Australia

• Premier of New South Wales – Bob Carr
  • Opposition Leader – John Brogden
• Premier of Queensland – Peter Beattie
  • Opposition Leader – Lawrence Springborg
• Premier of South Australia – Mike Rann
  • Opposition Leader – Rob Kerin
• Premier of Tasmania – Jim Bacon (until 21 March), then Paul Lennon
  • Opposition Leader – Rene Hidding
• Premier of Victoria – Steve Bracks
  • Opposition Leader – Robert Doyle
• Premier of Western Australia – Geoff Gallop
  • Opposition Leader – Colin Barnett
• Chief Minister of the Australian Capital Territory – Jon Stanhope
  • Opposition Leader – Brendan Smyth
• Chief Minister of the Northern Territory – Clare Martin
  • Opposition Leader – Terry Mills
• Chief Minister of Norfolk Island – Geoffrey Gardner

• Governor of New South Wales – Marie Bashir
• Governor of Queensland – Quentin Bryce
• Governor of South Australia – Marjorie Jackson-Nelson
• Governor of Tasmania – Richard Butler (until 9 August), then William Cox (from 15 December)
• Governor of Victoria – John Landy
• Governor of Western Australia – John Sanderson
• Administrator of the Australian Indian Ocean Territories – Evan Williams
• Administrator of Norfolk Island – Grant Tambling
• Administrator of the Northern Territory – Ted Egan

• 2 January - "Crocodile Hunter" Steve Irwin feeds a crocodile at his famous Australia Zoo while holding his one-month-old baby son, Robert Irwin. The incident generates a great deal of criticism both nationally and internationally over the next few days.
• 8 January - 33 asylum seekers detained on Nauru decide to suspend their month-long hunger strike after hearing of plans for an Australian medical team to travel to the island.
• 13 January – The Spirit of Tasmania III makes its inaugural trip from Sydney to Devonport. It ceased in 2006
• 16 January -
  • Prime Minister John Howard discusses the issues of security and missile defense with the United States Chairman of Joint Chief of Staff, General Richard Myers.
  • Queensland Premier Peter Beattie announces an election date of 7 February.
• 19 January - Cricketer David Hookes died after a fight outside a Melbourne pub.
• 23 January - The Queensland Crime and Misconduct Commission has found no evidence of any misconduct by the state's police or judiciary, or by politicians including Premier Peter Beattie and Federal MP Tony Abbott, in relation to the jailing last year of Pauline Hanson and David Ettridge.
• 28 January -
  • Port Kembla ethanol explosion in south Sydney.
  • Prime Minister John Howard and Foreign Minister Alexander Downer call for a sporting boycott in Zimbabwe.

• 1 February – The first Ghan passenger train across Australia from Adelaide to Darwin sets off on its three-day journey.
• 6 February – The Music Industry Piracy Investigations organization uses an Anton Piller order to raid offices of P2P companies Sharman Networks and Brilliant Digital Entertainment, the homes of their key executives, as well as several internet service providers and universities.
• 8 February – Peter Beattie's Australian Labor Party Queensland state government is re-elected in a landslide.
• 11 February – A Black Hawk helicopter reportedly crashed near Amberley air force base with at least five seriously injured.
• 14 February – Riots break out between police and Aboriginal residents of Sydney suburb Redfern
• 15 February – Violent riots ensue in the Sydney suburb of Redfern after an Aboriginal boy dies while allegedly fleeing police.
• 23 February – Tasmanian Premier Jim Bacon resigns after being diagnosed with inoperable lung cancer, handing power to his deputy, Paul Lennon.
• 25 February – Qantas launches its discount domestic airline, Jetstar.
• 29 February – Malcolm Turnbull controversially wins Liberal pre-selection for the federal seat of Wentworth, displacing sitting member Peter King.

• 3 March - A bottle of wine is discovered on board the Queensland Government jet when Indigenous Policy Minister Liddy Clark and her staff visit an alcohol-free Indigenous community at Lockhart River, about 800  km north of Cairns, Queensland.
• 11 March – A Senate report on poverty is immediately dismissed by Prime Minister John Howard. The report shows between 2 and 3.5 million Australians, or up to 19 percent of the population, are living in poverty.
• 20 March - Van Tuong Nguyen is sentenced to death in the Singaporean High Court after being convicted of trafficking 396.2g of heroin into Singapore in December 2002.
• 27 March - Brisbane City Council Elections. Liberal candidate Campbell Newman becomes Lord Mayor of Brisbane defeating Labor candidate Tim Quinn, thus ending 13 years of Labor government in Brisbane.

• 5 April – Australia's biggest supplier of the potential explosive ammonium nitrate decides to pull the product from its stores in response to concerns it could be used by terrorists.
• 14 April – The Family Court allows a thirteen-year-old child, born female, to start preliminary hormone treatment: the child identifies as being male and has been suffering from gender identity disorder.
• 24 April – John Howard joins Australian troops in Baghdad for ceremonies honoring the country's war dead.

• 14 May – Hobart woman Mary Donaldson marries Frederick, Crown Prince of Denmark in Copenhagen to become Mary, Crown Princess of Denmark
• 18 May - The Australia-United States Free Trade Agreement is signed.
• 25 May – Jetstar Airways commences operations with a maiden flight from Newcastle to Launceston via Melbourne.
• 31 May - The ABC airs an episode of "Play School" featuring a segment about a little girl and her two "mums". The segment was criticised for exposing children to issues of sexuality.

• 1 June – Australian Jennifer Hawkins wins the Miss Universe contest, held in Quito, Ecuador.

Defence Minister Robert Hill admits that his office knew of allegations of abuse of Iraqi prisoners.

• 2 June - Former Qantas baggage handler, 34-year-old Bilal Khazal, is arrested outside his home at Lakemba, in Sydney's south-west, charged with collecting or making documents likely to facilitate terrorist acts. It's the first time someone has been charged with this offense since the laws were passed in 2002.
• 3 June – United States President George W. Bush publicly supports Prime Minister John Howard and criticises Opposition Leader Mark Latham, sparking criticism from the Opposition for intervening in Australian domestic politics.
• 8 June - A post-mortem examination report is released which reveals that euthanasia crusader, Nancy Crick, had no cancer in her body at the time she took her life on 21 May 2002.
• 15 June - Prime Minister John Howard releases the Government's Energy Statement which introduced the term "Mandatory Renewable Energy Target", benchmarks set by the government for the amount of non-polluting energy that Australia uses. Australia's current target is two percent renewable energy.
• 16 June - Defence Minister Robert Hill releases his long-awaited statement to the Senate explaining how it was that he and Prime Minister, John Howard, misled Parliament over Defence knowledge of Iraqi prisoner abuse at Abu Ghraib prison.
• 24 June - Federal Sports Minister Rod Kemp releases details of an inquiry into sports doping. Retired Justice Robert Anderson has one week to question the five implicated cyclists, and use scientific testing to show Cycling Australia and the Australian Olympic Committee that the athletes have no case to answer.
• 25 June -
  • The New South Wales Government rushes new water laws through Parliament.
  • The Premier's Conference is held in Canberra.

• 2 July - Federal Opposition Leader Mark Latham denies having "king hit" a constituent when he was a councilor on Liverpool Council in Sydney during the 1980s.
• 5 July –
  • Australia and Thailand sign a free trade agreement.
  • Federal Opposition Leader Mark Latham calls an extraordinary media conference to deal with the circulating rumors about him.
• 30 July - Australian cyclist, Jobie Dajka, is dropped from the Australian Athens Olympic team after he admitted to lying to the Robert Anderson doping inquiry. His DNA has been found on syringes and vials in the room of disgraced cyclist Mark French at the Australian Institute of Sport in Adelaide.

• 3 August - President George W. Bush signs the United States-Australia Free Trade Agreement Implementation Act into law.
• 6 August -
  • In a 4–3 ruling, the High Court finds that the existing immigration laws are valid and that failed asylum seekers who cannot be deported can be held in detention indefinitely.
  • The leader of the extreme right-wing Australian Nationalists Movement in Western Australia, Jack van Tongeren, is taken into custody by police. Police were seeking the self-proclaimed white supremacist to question him about racist graffiti attacks in Perth.
  • Gavin Hopper, former tennis coach of Mark Philippoussis, is sentenced in Melbourne over the indecent assault of one of his 14-year-old pupils at Wesley College.
• 9 August – Richard Butler, the controversial governor of Tasmania, resigns.
• 13 August - The Australia-United States Free Trade Agreement Implementation Act is passed by the Senate, with amendments. The Labor Party had insisted on amendments designed to protect cheap generic medicine manufacturers.
• 16 August - Michael Scrafton, a former senior adviser to Peter Reith, reveals that he told John Howard on 7 November 2001 that the Children Overboard claim might be untrue. Mr. Howard said they only discussed the inconclusive nature of the video footage. In light of the new information, the Labor opposition called for a further inquiry, which was convened on 1 September.
• 17 August - Federal Opposition Leader Mark Latham is hospitalized after being diagnosed with pancreatitis.
• 20 August -
  • United States Ambassador to Australia, Tom Schieffer, makes it clear he expects Australia would help the United States defend Taiwan if China invaded Taiwan.
  • The New South Wales Independent Commission Against Corruption (ICAC) sends Premier Bob Carr a summons to appear before the commission on a charge of contempt. The Opposition called for his resignation.
• 29 August – John Howard announces that the 2004 federal election will take place on 9 October

• 1 September -
  • Senator George Brandis presents telephone records to the Senate Inquiry into the "Children Overboard" affair in a bid to discredit claims by former government adviser, Michael Scrafton, that he told Prime Minister, John Howard, that there was no evidence to support claims made about asylum seekers throwing their children into the sea.
  • Prime Minister John Howard denies having lied to the Australian public about "children overboard".
  • Australian Olympic athletes returned from the Athens Olympic Games.
• 8 September - British Airways announces that it is selling its $1.1 billion stakes in Qantas in order to cut debt and fund possible acquisitions. The sale ends an 11-year relationship between the two airlines.
• 9 September – A bomb blast outside the Australian embassy in Jakarta, Indonesia, kills eleven people and injures up to 100 people.
• 17 September - Federal Treasurer Peter Costello unveils the updated estimate of the national GST revenue. Prime Minister John Howard says the States will receive $3 billion more revenue than expected as a result.
• 29 September - Mark Latham officially launches the Labor Party's election campaign.
• 30 September - The President of Nauru, Ludwig Scotty, declared a state of emergency, dissolved Parliament and set an election date of 23 October.

• 9 October – The Liberal Party of Australia government of John Howard is returned for a fourth term at the 2004 federal election.
• 12 October –
  • Simon Crean resigns from the position of Shadow Treasurer, requesting a lesser portfolio, and John Faulkner resigns as Leader of the Opposition in the Senate in the aftermath of the Australian Labor Party's election loss.
  • Numerous Australians visit Kuta, Bali, to commemorate the second anniversary of October 2002 Bali bombing, with services being held across the nation.
• 14 October –
  • Annette Ellis stands down as Shadow Minister for Ageing, Seniors, and Disabilities.
  • The successful tenderer for Melbourne's Mitcham-Frankston Freeway is announced, with tolls due to be set at $4.43 for a one-way trip.

• 15 November - The Cairns Tilt Train derailment occurred at 11:55 pm, when the City of Townsville diesel tilt train derailed north of Berajondo, approximately 342  km (213  mi) north-west of Brisbane, Queensland.
• 26 November – A riot occurs on Palm Island leading to a complete break down of law and order with the 18 members of the Queensland Police barricading themselves in the local hospital.

• 7 December – Heavy rain causes flash flooding on Queensland's Gold Coast overnight. 200mm of rain fell in the afternoon and early evening.
• 26 December – 26 Australians are among the victims of the 2004 Indian Ocean tsunami, including the Australian football player Troy Broadbridge.