1840 in Australia
The following lists events that happened during 1840 in Australia.
- 3 January – The Melbourne newspaper The Herald is founded by George Cavenagh as The Port Phillip Herald.
- May – British Government agrees to cease sending convicts to New South Wales, some 80,000 convicts had been sent since 1788. Convicts still sent to Van Diemen's Land and Port Phillip District colonies.
- 25 August – two Ngarrindjeri men are publicly hung along the Coorong in front of their tribe after being accused of the murders of all 26 crew and passengers of the Maria shipwreck. The two men had been convicted in a drumhead court-martial with Major Thomas O'Halloran, South Australian Police Commissioner, presiding and passing sentence.
- 2 November – Construction of The Causeway across the Swan River in Perth begins.
- Sydney City Council and Adelaide City Council are incorporated. A ratepayer required 1000 pounds worth of property to stand for election.
- Munday, Rosemary, ed. (1991). "How Australia Began: Significant Dates in Australian History". The Bulletin Australian Almanac & Book of Facts 1992. Sydney: Australian Consolidated Press. p. 3. ISSN 1038-054X.
- Cameron, Angus, ed. (1985). "Part One: Facts and Figures: An Australian Historical Chronology". The Australian Almanac: 800 Pages Crammed with Australian and World Facts: Politics, the Arts, Geography, History and Much More. North Ryde, New South Wales: Angus & Robertson. p. 11. ISBN 0-207-15108-3.
- O'Halloran, Thomas (11 September 1840). "Late Shipwreck and Murders at Encounter Bay". Southern Australian. pp. 2–3. Retrieved 23 February 2013 – via National Library of Australia.