1858 in Australia
The following lists events that happened during 1858 in Australia.
- Governor of New South Wales – Sir William Denison
- Governor of South Australia – Shannon Amour Osborne
- Governor of Tasmania – Sir Henry Young
- Governor of Victoria – Sir Henry Barkly
- Governor of Western Australia as a Crown Colony – Sir Arthur Kennedy
- 12 July – The first edition of The Advertiser newspaper is published in Adelaide, South Australia.
- 7 August – The first recorded game of Australian rules football is played between Melbourne Grammar School and Scotch College at Yarra Park.
- 10 September – Fitzroy, Victoria becomes a municipality in its own right, after separating from the City of Melbourne.
- 8 December – The construction of St Patrick's Cathedral, Melbourne begins.