The following lists events that happened during 1904 in Australia.

Alfred Deakin

Chris Watson

George Reid

• Monarch – Edward VII
• Governor-General – Hallam Tennyson, 2nd Baron Tennyson (until 21 January), then Henry Northcote, 1st Baron Northcote
• Prime Minister – Alfred Deakin (until 27 April), Chris Watson (until 18 August), then George Reid
• Chief Justice – Samuel Griffith

• Premier of New South Wales – John See (until 14 June), Thomas Waddell (until 29 August), then Joseph Carruthers
• Premier of South Australia – John Jenkins
• Premier of Queensland – Arthur Morgan
• Premier of Tasmania – William Propsting (until 12 July), then John Evans
• Premier of Western Australia – Walter James (until 10 August), then Henry Daglish
• Premier of Victoria – William Irvine (until 16 February), then Sir Thomas Bent

• Governor of New South Wales – Sir Harry Rawson
• Governor of South Australia – Sir George Ruthven Le Hunte
• Governor of Queensland – Sir Herbert Chermside (until 10 October)
• Governor of Tasmania – Captain Sir Arthur Havelock (until 16 April), then Sir Gerald Strickland (from 28 October)
• Governor of Western Australia – Admiral Sir Frederick Bedford
• Governor of Victoria – Major General Sir Reginald Talbot (from 25 April)

• 6 January – The Tasmanian government replaces the state's Central Board of Health with a Public Health Department.
• 13 January – The flag of South Australia is officially gazetted as the current design.
• 23 January – A by-election is held for the New South Wales Legislative Assembly seat of Ryde. It is won by Edward Terry for the Liberal Reform Party.
• 29 February – Women's suffrage is granted in Tasmania.
• 1 June – A general election is held in Victoria. Incumbent premier Sir Thomas Bent is returned with an increased majority.
• 20 June – The P&O ship SS Australia is wrecked at the entrance to Port Phillip. There is no loss of life.
• 12 November – John Drayton is imprisoned under parliamentary privilege provisions in Western Australia.
• 1 December – Ipswich, Queensland is proclaimed as a city.

• 12 January – Melbourne businessman Alfred Felton leaves a large bequest to the Art Gallery of Victoria.
• Hans Heysen wins the Wynne Prize with Mystic Morn
• The Austral Hall Toowoomba was officially opened on 5 November 1904 by Sir Hugh Nelson, Lieutenant Governor of Queensland for The Austral Society.

• September – The Australasian Lawn Tennis Association is formed in Sydney.
• 1 November – Acrasia wins the Melbourne Cup.
• New South Wales wins the Sheffield Shield.
• Two Australians, Corrie Gardner and Leslie McPherson, compete in athletics at the 1904 Summer Olympics. They do not return with any medals

• 7 April – Sir Roland Wilson, public servant and economist (d. 1996)
• 8 April – John Antill, composer (d. 1986)
• 29 May – Sir Hubert Opperman, Victorian politician and cyclist (d. 1996)

• 8 January – Alfred Felton, entrepreneur, art collector and philanthropist (born in the United Kingdom) (b. 1831)
• 25 January – Sir Graham Berry, 11th Premier of Victoria (born in the United Kingdom) (b. 1822)
• 2 February – Sir Edward Braddon, 18th Premier of Tasmania (born in the United Kingdom) (b. 1829)
• 12 April – George Cruickshank, New South Wales politician (b. 1853)
• 12 May – Robert Reid, Victorian politician (born and died in the United Kingdom) (b. 1842)
• 5 August – Sir George Dibbs, 10th Premier of New South Wales (b. 1834)
• 17 December – William Shiels, 16th Premier of Victoria (born in Ireland) (b. 1848)

• 1904
• 1900–1909