Dr Jim Cairns (October 4, 1914 - October 12, 2003) was an Australian politician, Deputy Prime Minister and Treasurer (1974-5) in Gough Whitlam's Labor Government. During and shortly after his holding Australia's second-highest political office, Cairns's writings became increasingly counter-cultural, influenced by such writers as Wilhelm Reich.

Cairns is best remembered as a leader of the Anti-Vietnam War movement during Australia's long and controversial involvement in that War, but also for his affair with Juni Morosi (sometimes spelled Junie Morosi) and for his later renunciation of conventional politics.

After leaving politics he became a leading light of the counter-cultural Down to Earth movement which organised ConFests (such as the December 12, 1976, Cotter ConFest) attended by tens of thousands of Australians interested in alternative lifestyles.

In a 1982 defamation case he initiated before the Supreme Court of the State of New South Wales, Cairns denied on oath having had a sexual relationship with Juni Morosi. The jury in that case found that the article in question did contain "an imputation" that Cairns was "improperly involved with his assistant, Junie Morosi, in a romantic or sexual association," but that this statement was not defamatory. Cairns did not receive money for defamation, although Morosi did. In 2002 Cairns admitted that he had had a sexual relationship with Morosi.