Polygamy is not permitted in Australia. Polygamous marriages may not be performed in Australia, and a person who marries another person, knowing that the previous marriage is still subsisting, commits an offence of bigamy under section 94 of the Marriage Act 1961, which carries a maximum penalty of 5 years imprisonment. Whether or not either or both partners were aware of the previous subsisting marriage, the second marriage is void. Foreign polygamous marriages are not recognized in Australia. However, a foreign marriage that is not polygamous but could potentially become polygamous at a later date under the law of the country where the marriage took place is recognized in Australia while any subsequent polygamous marriage is not. Australia's former Attorney GeneralRobert McClelland has said that "There is absolutely no way that the government will be recognising polygamist relationships. They are unlawful and they will remain as such. Since 9 January, 2018 under Australian law, marriage is defined as "a union of 2 people to the exclusion of all others". Polygamous marriage necessarily offends this definition." Former High Court Judge, the Hon. Michael Kirby said in 2012, "Human relationships are complicated, but these, I would respectfully suggest, are issues for the future".
On March 4, 2016, the Full Court of the Family Court of Australia ruled that a polygamous marriage is illegal in Australia but a foreign marriage, which is ‘potentially polygamous’ when it is entered into, will be recognised as a valid marriage in Australia. A marriage is ‘potentially polygamous’ if it is not polygamous but the law in the country where the original marriage took place allows a polygamous marriage of one or both partners to the original marriage at a later date. The court also ruled that if the husband took a second wife, the second marriage would not be legally recognised while the husband was still married to his first wife.
Social security
Australian social security law recognises that multiple partners are assessed exactly the same as any other person, with no additional payments for having multiple partners.
A small number of Islamist leaders advocated the legalisation of polygamous marriages in Australia, which stirred controversial and emotional debate. On an SBS, Insight program seeking to answer the question, "How common is polygamy in Australia?", panelist Fatimah Youssef said that polygamy is common in her local Lebanese Muslim community in Sydney. Proponents of polygamy have claimed that legalisation would "protect the rights of women," while opponents have claimed that it would "endanger the Australian way of life."
General community
In the 2012 Sydney Gay and Lesbian Mardi Gras which was themed "universal and infinite love", the polygamy float featured a, "huge retro style rocket ship". The 2014 Mardi Gras hosted the, "Polyamory Sydney ‘Birds of a Feather, love together’ – the infinite love Nest". In 2013, the 'Polyamory Action Lobby' submitted a petition to federal parliament saying, "For too long has Australia denied people the right to marry the ones they care about. We find this abhorrent. We believe that everyone should be allowed to marry their partners, and that the law should never be a barrier to love. And that's why we demand nothing less than the full recognition of polyamorous families." In 2014 and 2015 further recognition for, and acceptance of, polygamy was sought A number of Australian Facebook sites are dedicated to polygamy, including 'Sydney Polyamory' and 'Poly Mardi Gras Float'. A website set up to assist men in finding a second wife is reported to have 750 Australian members. Polyamory groups in Sydney and Brisbane have a reported 1,900+ members. The functioning of monogamish and trouple relationships are being explored. Concern has been raised with both redefining relationships as, "primarily about adult desire".
