- McEwen Government, December 18: Prime Minister Harold Holt disappears in the surf at Portsea, Victoria on 17 December. His body is never recovered.
- A record national referendum vote of 90.8% approves the ending of constitutional discrimination against Aborigines. The "Yes" vote affirms the Australian citizenship of indigenous Australians (accepting that Aboriginal people be counted in the census) and allows the Commonwealth Government to legislate on their behalf. The referendum gives Aborigines some of the status that the Constitution of 1901 had not provided.
- The first US naval communications base in Australia is opened at North West Cape, WA.
† Australia's Prime Ministers