1845 in Australia

• Monarch - Victoria

Governors of the Australian colonies:

• Governor of New South Wales – Sir George Gipps
• Governor of South Australia – Sir George Grey (to 25 October), then Lieutenant Colonel Frederick Holt Robe
• Governor of Tasmania – Sir John Eardley-Wilmot
• Governor of Western Australia as a Crown Colony – John Hutt.

• 12 March – St John the Baptist Church in Reid Canberra is consecrated.
• 4 August – The ship Cataraqui is wrecked off the coast of Tasmania, the 406 people on board drown.
• 20 July – Charles Sturt enters the Simpson Desert in central Australia.
• 21 June – News of the discovery of a rich body of copper ore at Burra, South Australia is published in Adelaide newspapers.
• 17 December – Ludwig Leichhardt arrives at Port Essington, Northern Territory, after an overland journey of 4800 km from Jimbour on the Darling Downs.^[1]
• Undated – Port Augusta War ends^[2]
• Undated – An unknown number of Indigenous Australians are killed in the Darkey Flat massacre.
• Wool export in Australia – 24 million pounds.

• 12 January – Walter Howchin, geologist (born in the United Kingdom) (d. 1937)
• 11 February – John Chanter, New South Wales politician (d. 1931)
• 16 February – Maybanke Anderson, suffragette and reformer (born in the United Kingdom) (d. 1927)
• 17 February – Percival Ball, sculptor (born in the United Kingdom) (d. 1900)
• 25 February – Sir George Reid, 4th Prime Minister of Australia and 12th Premier of New South Wales (born in the United Kingdom) (d. 1918)
• 20 March – Victor Child Villiers, 7th Earl of Jersey, 17th Governor of New South Wales (born in the United Kingdom) (d. 1915)
• 3 April – William Farrer, agronomist (born in the United Kingdom) (d. 1906)
• 15 April – Dave Gregory, cricketer (d. 1919)
• 16 June – William Charles Kernot, engineer (born in the United Kingdom) (d. 1909)
• 21 June
  • Henry Brockman, Western Australian politician (d. 1916)
  • Sir Samuel Griffith, 9th Premier of Queensland and 1st Chief Justice of Australia (born in the United Kingdom) (d. 1920)
• 19 October – Frank Hann, pastoralist and explorer (born in the United Kingdom) (d. 1921)
• 21 October – Ernest Favenc, explorer, journalist and author (born in the United Kingdom) (d. 1908)
• 15 December – Thomas Skene, Victorian politician (d. 1910)
• 30 December – Thomas Edward Spencer, writer (born in the United Kingdom) (d. 1911)

• 5 August – John Blaxland, New South Wales politician and explorer (born in the United Kingdom) (b. 1769)