1870 in Australia

Incumbents

Governors

• Governor of New South Wales – Somerset Lowry-Corry, 4th Earl Belmore
• Governor of Queensland – Colonel Sir Samuel Blackall
• Governor of South Australia – Sir James Fergusson, 6th Baronet
• Governor of Tasmania – Charles Du Cane
• Governor of Victoria – John Manners-Sutton, 3rd Viscount Canterbury

  Premiers

• Premier of New South Wales – John Robertson, until 13 January then Charles Cowper, until 16 December then James Martin
• Premier of Queensland – Charles Lilley, until 3 May then Arthur Hunter Palmer
• Premier of South Australia – Henry Strangways, until 30 May then John Hart
• Premier of Tasmania – James Milne Wilson
• Premier of Victoria – John Alexander MacPherson, until 9 April then James McCulloch

  Events

• 3 January – A state flag of Western Australia is adopted.
• 1 February – A state flag of Victoria is adopted, although with no crown like the current flag.
• 22 March – A state flag of Queensland is adopted, with a portrait of Queen Victoria.
• 20 April – A second state flag of New South Wales is adopted, similar to the current flag of Victoria: a crown above the Southern Cross.
• 22 July – A state flag of South Australia is adopted.
• 11 August – Melbourne Town Hall is opened.

  Exploration and settlement

• Gulgong, New South Wales, is founded.
• 27 August – John Forrest successfully arrives in Adelaide from Perth, leading an expedition along the south coast via the Great Australian Bight.

  Science and technology

• September – Work begins on the Australian Overland Telegraph Line linking Port Augusta to Darwin.

  Sport

• 12 May – Port Adelaide Football Club is founded in South Australia

  Births

• 3 January – Ethel Richardson, author, better known by her nom de plume Henry Handel Richardson
• 17 May – Newton Moore, Premier of Western Australia
• 1 November – Christopher Brennan, poet

  Deaths

• 23 May - Foster Fyans, first mayor of Geelong
• 25 May - Captain Thunderbolt, bushranger
• 24 June - Adam Lindsay Gordon, poet