1799 in Australia
- 7 January – Bass and Flinders complete their circumnavigation of Van Diemen’s Land in sloop Norfolk.
- 11 February – The gaol in Sydney is burned by arsonists.
- 3 March – Hawkesbury River floods, killing one.
- 12 March – Isaac Nichols is accused of stealing stolen goods and sentenced to 14 years on Norfolk Island; his sentence is suspended by Governor Hunter on 1 April
- 8 July – Matthew Flinders leaves Port Jackson to explore the East coast in sloop Norfolk; he surveys Moreton Bay between the 15th and 31st and charts Hervey Bay on 2 August. He returns to Sydney on 20 August.
- 18 October – Five settlers are found guilty of killing aborigines in the Hawkesbury, they are later pardoned.
- 5 November – Hunter is recalled and Philip Gidley King is named as his successor
- 28 December – The gaol in Parramatta is lost to arson.
- 26 January – Thomas Muir