1803 in Australia

Decades:	1780s; 1790s; 1800s; 1810s; 1820s;
See also:	Other events of 1803; ; Timeline of Australian history;

The following lists events that happened during 1803 in Australia.

Incumbents

14 January – Lieut-Col David Collins is commissioned in England to found a new settlement on Bass Strait, preferably at Port Phillip.
5 March – George Howe publishes the first issue of the weekly The Sydney Gazette and The New South Wales Advertiser, Australia's first newspaper.
19 April - Governor King proclaims toleration for Catholics and allows Fr James Dixon to say mass for Irish convicts.^[1]^[2]
14 May - Illegal Masonic meeting held in Sydney and all participants arrested.^[2]
25 November - William James Hobart Thorne is the first white child born in Victoria^[3] when he is born at Port Phillip, in what was then part of New South Wales but later became Victoria.^[4] He dies on 2 July 1872.
27 December – Convict William Buckley escapes from Sullivan Bay, Victoria. He lives with the Wautharong Aboriginal people for 32 years.
26 June – John Macarthur writes the Statement of Improvement and Progression of Fine Woolled Sheep in New South Wales.

January–February – Acting Lieutenant Charles Robbins and NSW Surveyor General Charles Grimes survey Port Phillip in HMS Cumberland
2 February – Charles Grimes discovered the Yarra River.
9 June – Investigator arrives in Port Jackson after circumnavigating Australia. On the voyage Matthew Flinders charted the coast and Robert Brown made an extensive collection of the flora of Australia.
11 September – John Bowen with a party of forty-eight found the first settlement in Van Diemen's Land near the Derwent River.
9 October – David Collins, on HMS Calcutta and Ocean, establishes the short-lived settlement at Sullivan Bay on Port Phillip

^ Proclamation, Sydney Gazette and New South Wales Advertiser, 24 Apr 1803
^ ^a ^b Franklin, James (2021). "Sydney 1803: When Catholics were tolerated and Freemasons banned" (PDF). Journal of the Royal Australian Historical Society. 107 (2): 135–155. Retrieved 27 December 2021.
^ "The Late Robert Thorne". The Mercury (Hobart). Vol. LIV, no. 6, 116. Tasmania, Australia. 27 September 1889. p. 2. Retrieved 2 November 2019 – via National Library of Australia.
^ "Finding Settlements First Son". The Age. 16 November 2003. Retrieved 7 November 2019.