the severe drought which has stricken large areas of Australia since 1957, particularly in rural NSW and Queensland, is finally eased by widespread rains
Jørn Utzon resigns as architect of the Sydney Opera House, following a bitter struggle with the new Public Works Minister Davis Hughes over fees, costs and design changes
The first National Service conscripts fly out from Richmond RAAF base in Sydney bound for Vietnam
7 April – New South Wales repeals the Sunday Observance Act, allowing theatres and cinemas to open, sporting events to charge admission and clubs to sell alcohol on Sundays.
the Federal government announces the formation of a military Task Force (including conscripts), increasing Australia's commitment to the Vietnam War to 4,500.
US Vice-President Hubert Humphrey visits Australia to assure the Australian government that the war is being directed by Hanoi and Peking, and that it represents one of China's numerous offensives in Asia
Victoria extends hotel trading hours from 6pm to 10pm, ending the infamous "Six O'Clock Swill". Driving with a blood alcohol level over 0.05% becomes a criminal offence.
On advice from Immigration Minister Hubert Opperman, federal cabinet reverses a decision of September 1964, agreeing that non-Europeans could be selected on an individual basis to enter as immigrants with permanent resident status and naturalisation on an equal basis with European applicants
The Arbitration Commission introduces a minimum weekly wage for adult male employees under federal awards
Australian forces engage in their first major battle in Vietnam at the Battle of Long Tan, inflicting heavy losses on NLF troops
26 November – The Liberal government of Harold Holt scores a massive victory in the 1966 federal election, and is returned to power with the largest majority in the federal parliament's 65-year history.
Science and technology
Sydney industrial designer Harry Widmer wins the prestigious F.H. Edwards Laurel Award for his design for the Kriesler Mini 41–47 portable radio. The 41-47's innovative polypropylene plastic casing is the first use of this material anywhere in the world in consumer electronics
Australia's first satellite communications earth station opens at Carnarvon in WA
