3 January – The Clean Ocean Foundation bans Victorian Premier Steve Bracks from Gunnamatta Beach over delays to upgrade a treatment plant that is allowing effluent to be dumped at sea.
17 January – West Australian Premier Geoff Gallop and the State Government decide to support a yes-yes vote in a referendum favouring extended late night and Sunday trading.
18 January – Mark Latham quits as Federal Opposition Leader, resigns his seat in Parliament.
Immigration Minister Amanda Vanstone announces a closed inquiry to be headed by former AFP commissioner Mick Palmer, to investigate how Cornelia Rau came to be held in solitary confinement at Baxter Detention Centre and why she did not receive treatment despite having schizophrenia.
Queensland Senator Santo Santoro raises the issue of abortion at the Coalition Party Room meeting in Canberra by circulating a policy paper with recommendations aimed at reducing the number of abortions, such as a Medicare-funded ultrasound for women contemplating an abortion, along with some Medicare-funded counselling.
9 February – Queensland Premier Peter Beattie releases an edited transcript of an interview between Cornelia Rau and officers at the Brisbane Women's Correctional Centre on 5 July 2003.
10 February –
Queensland Premier Peter Beattie apologises for the failure of his agencies to properly care for Cornelia Rau.
Local Government Minister Jim Lloyd denies allegations that his office was involved in a conspiracy to defraud the Commonwealth over a one-and-a-half million dollar grant to dredge the Tumbi Creek on the New South Wales central coast.
11 February – Immigration Minister Amanda Vanstone admits that criminals who have finished their prison sentences and are awaiting deportation are being held among asylum seekers at the Baxter Detention Centre.
13 February – Federal Treasurer Peter Costello breaks ranks with Prime Minister John Howard and says he and the government are sorry for the way Cornelia Rau was treated.
19 February – Prime Minister John Howard and New Zealand Prime Minister Helen Clark meet for talks.
21 February – Health Minister Tony Abbott is reunited with what he believes to be his son, who was given up for adoption as a baby.
24 February - the Nintendo DS is released in Australia.
26 February – The ALP government of Geoff Gallop is re-elected in Western Australia for a second term.
27 February – Immigration Minister Amanda Vanstone announces an extension of the Rau inquiry from original date of 24 March. Neil Comrie, the former Victorian Police Commissioner, is recruited to help Mick Palmer in the inquiry investigations.
17 March – News Limited newspapers report that Liberal Senator Ross Lightfoot, while on a parliamentary tour to Iraq, smuggled US$20,000 into the country on behalf of Woodside Petroleum as a donation for the Kurdish government, having been issued with a pistol for personal security. The newspapers published photographs of Mr. Lightfoot appearing with Kurdish militants wielding an AK-47. Mr. Lightfoot strenuously denies the allegations and threatens legal action against the newspapers carrying the story.
18 March – Prime Minister John Howard admits that Liberal Senator Ross Lightfoot has changed his story regarding the Cash for Kurds affair.
20 March –
Prime Minister John Howard confirms that some aspects of the Federal Government's immigration detention policies are under review.
Labor wins the seat of Werriwa.
21 March – Federal Government backbenchers, churches and the Family First Party lobby for the Federal Government to relax its refugee policy for Christian converts, but Prime Minister John Howard announces that no special treatment will be given.
22 March –
Stuart Copeland, the Queensland Shadow Minister for Health, raises the issue of Doctor Jayant Patel's clinical practice during Question Time in the Queensland Parliament. Copeland had been alerted to Patel's inadequacies by Toni Hoffman, a nurse at the Bundaberg Base Hospital.
Federal Health Minister Tony Abbott announces that his alleged long lost son is actually the son of another man, according to DNA testing.
24 March – Prime Minister John Howard puts state Labor governments on notice to cut taxes or else, giving them four weeks to comply.
25 March – Rob Messenger, the National Party Member of Parliament for Burnett, raises the matter of Doctor Jayant Patel in a speech to the Queensland Legislative Assembly. He calls for Patel's suspension.
9 April – Queensland Health Minister Gordon Nuttall announces an inquiry into patient safety at Bundaberg Base Hospital in the wake of the "Dr Death" controversy at the hospital.
11 April – Victorian Premier Steve Bracks unveils a plan to increase Melbourne's migration intake.
14 April – Queensland Premier Peter Beattie unveils plans to build a rail tunnel under the Brisbane River.
15 April – Prime Minister John Howard apologises for breaking his Medicare safety net election promise.
18 April - A fifteen-year-old known as "Tram Boy" allegedly stole a tram in Melbourne. Tram boy drove around on the network for 40 minutes before being stopped by police
May
1 May – Federal Treasurer Peter Costello warns of Liberal Party instability if John Howard does not hand over the Prime Ministership.
2 May – Douglas Wood is taken hostage in Iraq. He is later rescued on 15 June.
6 May – The scandal concerning the 2001 deportation the Philippines of Australian resident Vivian Solon first comes to light.
19 May – Prime Minister John Howard admits he has no proof that a Muslim cleric spoke to Douglas Wood.
23 May – The Morris Inquiry into the Queensland public hospital system (headed by Tony Morris QC) begins in Brisbane.
25 May – New South Wales Premier Bob Carr becomes the State's longest serving Premier.
27 May – Schapelle Corby convicted of drug smuggling by an Indonesian court, and sentenced to 20 years in prison (later reduced to 15 and then reverted to 20 years).
Prime Minister John Howard stands by the Special Air Service Regiment against allegations in Time Magazine that Australian SAS soldiers killed innocent tribesmen in Afghanistan.
The Federal Government announces an independent audit of airport security.
3 June – The Council of Australian Governments (COAG) meeting between the State Premiers and the Prime Minister is held. The Premiers agree to disagree with the Prime Minister on industrial relations, but make a commitment to the establishment of a national system of apprenticeships to address the skills shortage.
8 June – Queensland Premier Peter Beattie announces approval for $60,000 in retrospective travel expenses for former Speaker Ray Hollis.
28 June – Three suspects in a 2002 gang rape in Hurstville finally arrested in dawn raids in New South Wales.
29 June – Rain brings drought relief and flooding across New South Wales.
New South Wales Supreme Court finds no evidence of neglect against Westmead Hospital in the Rhiannon Richards brain damage suit, leaving her family to pay both sides' legal costs.
New South Wales health authorities warn parents of an outbreak of whooping cough across the state, urging parents to immunise their children.
Controversial tax cuts, intended to boost family budgets, come into effect as the Federal Government officially takes control of the Senate.
A statewide two-hour teachers' strike takes place in New South Wales to protest proposed changes to Federal industrial relations laws.
14 July – Following the release of the Palmer Inquiry report, Prime Minister John Howard and Immigration Minister Amanda Vanstone apologise to Cornelia Rau, who was mistakenly held in detention for 10 months, and to Vivian Solon, who was deported to the Philippines. The 200-page report identified systemic weaknesses in the Department of Immigration which contributed to Ms Rau's detention, the failure to establish her identity, and to meet her mental health needs. The report says that those same mistakes were made in Vivian Solon's case.
23 July – Victorian Premier Steve Bracks outlines plans for a summit involving every regional mayor in Victoria, as well as announcing a new deal for a sustainable abalone industry.
26 July – Prime Minister John Howard meets with Iraqi Prime Minister Ibrahim Jaafari and was told that the Iraqi military no longer needs help from Australian troops as they begin to take over.
21 August – Michelle Leslie is arrested in Bali after being found with two ecstasy pills in her handbag at an open-air dance party just outside Kuta. She is found guilty, and sentenced to three months in prison on 18 November, but is released on 20 November as she had already served her sentence.
Prime Minister John Howard supports the right of Muslim girls to wear headdresses to school.
September
5 September – Prime Minister John Howard rejects calls to sack Health Minister Tony Abbott over his insensitive remarks in relation to the suicide attempt by John Brogden.
14 September – In New York City, at the biggest gathering of world leaders at the United Nations 2005 World Summit, Prime Minister John Howard announces that Australia will double its overseas aid donations to $4 billion per year, within five years.
17 September – Prime Minister John Howard delivers a rebuke to the United Nations during an address to world leaders.
28 September – Prime Minister John Howard meets oil company leaders over the use of biofuels.
October
5 October – The Opposition accused Queensland Premier Peter Beattie of covering up a letter from the Health Commissioner asking for a new inquiry into the health crisis.
31 October – Federal Opposition Leader Kim Beazley commits the Federal Labor Party to supporting the Government's anti-terror laws.
November
4 November –
The Federal Opposition accuses Federal Health Minister Tony Abbott of failing to act on a report urging the wider use of a class of drugs which lower cholesterol and reduce the risk of strokes and heart attacks.
The Federal Government decides not to list the Aboriginal Tent Embassy on the Commonwealth Heritage Register despite a recommendation from the Australian Heritage Council to do so.
12 November – Prime Minister John Howard tells Australia's Islamic community that it is their duty to turn in anyone it believes to be an extremist.
17 November – Prime Minister John Howard is named in a video tape of the latest threat by Asia's most wanted terrorist.
27 November – At the Commonwealth Heads of Government Meeting (CHOGM) in Malta, Prime Minister John Howard makes a final plea to Singapore to spare the life of heroin trafficker, Van Nguyen, and makes it clear that Australians may resent Singapore if the hanging proceeds.
29 November – Prime Minister John Howard confirms that he will allow Coalition MPs to take part in conscience vote on whether to legalise the use of controversial abortion pill RU-486.
The Federal Government's sweeping industrial relations changes are endorsed by the Senate, along party lines, after a marathon sitting.
11–12 December – The 2005 Cronulla riots take place, with the rioting centred on Cronulla and other beachside suburbs. There is also rioting in the Greater Western Suburbs area of Sydney. Attacks on people of Middle Eastern appearance are also reported in Perth and Adelaide.
15 December – A Senate inquiry into the abortion drug RU-486 begins and the inquiry is told that Viagra is more dangerous than RU-486.
25 May – Graham Kennedy dies at age 71. The network on which most of his shows aired, the Nine Network, passes up the offer to broadcast his funeral & the Seven Network arrives, axes Nine's coverage and Seven picks it up and wins it. Nine does eventually show parts of the funeral live.
26 June – Douglas Wood is interviewed by Sandra Sully about his time as a captive after Network Ten pays a reported $400,000 for an exclusive interview.
15 August: Big Brother: Greg Mathew, along with twin brother David Mathew, also known as "The Logan Twins" is announced the winner of the fifth series.
20 November – Madonna's Warner Bros. single "Hung Up" defeats Gold Digger by Kanye West and Jamie Foxx to be crowned the title of the ARIA single debuting at No. 1. This was the last Top 50 ARIA charts on ABC TV's Rage to be shown on the Seven Network. Only Seven Local TV and ABC TV will continue the Rage's Top 50 Charts until the end of July 2006, when it launches jtv.
4 March – First day of the Australian Track & Field Championships for the 2004–2005 season, which are held at the Sydney Olympic Park in Homebush Bay. The 10,000 metres (men and women) were conducted at the Zatopek Meet in Melbourne, Victoria on Saturday 4 December 2004. The relays were conducted at Canberra on Sunday 6 February 2005.
19 March – Sydney Kings defeat Wollongong Hawks 112–85 in Game 3 of a series sweep in the NBL Grand Final series. The win completed the only three-peat in league history.
12 September – Cricket: England wins The Ashes back from Australia for the first time since 1987 in The 2005 Ashes series
24 September – The Sydney Swans (8.10.58) defeat the West Coast Eagles (7.12.54) to win the 109th VFL/AFL premiership. It is the first flag for the Swans in 72 years.
