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Polygamy in Australia

The word “polygamy” is ancient Greek for “married to many” or “often married”, and refers to a situation where a person has more than one concurrent marriage. Polygamy in Australia is illegal. Polygamy is legal in many African, Asian and Middle Eastern countries, and usually involves more than one wife. Polygamy is also common in certain religious groups in other countries, such as Mormons in the United States.

In Australia, it is a criminal offence to marry a person when already married to another, and is called bigamy. Bigamy is the act of going through a marriage ceremony; polygamy is the practice of having more than one spouse at one time.


Polygamous marriages are regulated under the Marriage Act 1961 and the Family Law Act 1975.

Section 94 of the Marriage Act sets out two ways bigamy can be committed:

“(1) A person who is married shall not go through a form or ceremony of marriage with any person.”


“(4) A person shall not go through a form or ceremony of marriage with a person who is married, knowing, or having reasonable grounds to believe, that the latter person is married.”

Both forms carry a maximum penalty of five years imprisonment. Although it is an indictable offence, bigamy falls within lower tier of indictable offences and can be dealt with summarily.

Under Australian law, however, it is not illegal to have multiple de facto relationships at the one time. Section 4AA(5)(b) of the Family Law Act explicitly allows that “a de facto relationship can exist even if one of the persons is legally married to someone else or in another de facto relationship”.

When polygamous marriages are recognised

Overseas marriages are recognised in Australia but the legislation restricts recognition of marriages conducted in countries where polygamy is permitted.

Section 6 of the Family Law Act states:

“For the purpose of proceedings under this Act, a union in the nature of a marriage which is, or has at any time been, polygamous, being a union entered into in a place outside Australia, shall be deemed to be a marriage.”

However, an overseas marriage will not be recognised if:

  • a party was aged under 16;
  • the union was non-consensual due to fraud, duress or mistaken identity;
  • the union was incestuous.

Defence to bigamy

It is a defence to prosecution of alleged bigamy if a person believed their spouse was dead. The Marriage Act states a period of seven years of continual absence is to be considered a sufficient period to establish a presumption of death.

The Act also provides that bigamy is not committed in situations where a person “goes through a form or ceremony of marriage with that person’s own spouse” such as when a couple renews their wedding vows or celebrates a second wedding.

In regards to evidence, the spouse of the accused “is a competent and compellable witness for either the prosecution or the defence” under s 94(6), but a marriage “shall not be taken to have been proved if the only evidence of the fact is the evidence of the other party to the alleged marriage” under s 94(7). A court can accept as evidence an original or certified copy of a certificate, entry or record of a marriage.

Preventing bigamy

The Marriage Act contains several provisions which operate to prevent bigamy. For instance:

  • s 23B(1)(a) makes any second or subsequent concurrent marriage legally void;
  • s 42 requires that for a marriage to be solemnised, it must take place before an authorised marriage celebrant, to whom official documents must be presented, including a written notice and declaration. The declaration must state the person’s current “conjugal status” and declare their “belief there is no legal impediment to the marriage”, which includes marriage to another person;
  • s 104 makes it an offence for a person to provide a notice to an authorised celebrant “if, to the knowledge of the person, the notice contains a false statement or an error or is defective”;
  • s 100 makes it an offence for a celebrant to solemnise a marriage where they believe there is a legal impediment to it or that it would be void.

Debate over polygamy in Australia

Polygamy in Australia has attracted attention in recent years as a result of the Plebiscite (Same-Sex Marriage) Bill 2016, due to its growing relevance in the family court system.

The most common argument put forward by opponents to polygamy in Australia is that is it anathema to women’s social, emotional and economic wellbeing. This is because polygamy is overwhelmingly practised as polygyny rather than polyandry, meaning men are entitled to have multiple wives but women are not entitled to have multiple husbands. This is said to perpetuate a patriarchal form of gender inequality, especially due to the fact the marriages are often arranged

Opponents say the payment of a “bride price” to the prospective husband leads to a woman being deemed as property, incentivising a family to marry off daughters at the first opportunity, and denying females the right to a life of their choice. They also point to other ramifications of a bride price, such as the propensity for large age gaps between husbands and wives, and the ensuing likelihood of early widowhood; and the entrapment of women in miserable or abusive unions. They say by its nature, polygamy causes emotional and financial isolation because it fosters neglect, jealousy, competition and conflict between a hierarchy of wives.

The welfare of children from polygamous relationships is also highlighted by opponents, who say such children experience hardship and psychological harm from isolation, stigmatisation, having a disordered mix of adult figures, and via a lack of connection to a single, dedicated family. They also point to evidence of sexual abuse, marrying of minors and marriage between close relatives, as documented in Mormon communities in the United States.

Proponents of polygamy argue that consenting adults should be free to enter marriages without the interference of the government. They say polygamy allows honesty in relationships, acts as a deterrent to infidelity for men and provides companionship for women. They argue arranged marriages promote or strengthen social, economic and political alliances, and that children of an “alpha male” stand to benefit from protection and influence.

They argue the practice can also provide a large support network for children of such relationships, including by exposing them to a broad range of adult role models. Further, they believe polygamy is a legitimate part of an already accepted shift away from the traditional two-parent paradigm. They claim the harms attributed to polygamous marriages may not be inherent to such relationships, and that such harms are already prohibited by law.

For advice on family law or any legal matter, please contact Armstrong Law.

Sally Crosswell

This article was written by Sally Crosswell

Sally Crosswell has a Bachelor of Laws (Hons), a Bachelor of Communication and a Master of International and Community Development. She also completed a Graduate Diploma of Legal Practice at the College of Law. A former journalist, Sally has a keen interest in human rights law.

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