Is polyamory legal?
In the countries we cover, being in loving relationships with more than one consenting adult is legal. What the law restricts is marriage: you cannot be legally married to more than one person at the same time. Beyond that headline, the details vary, and polyamorous families sometimes find that laws on parenting, property and inheritance were written with two-person couples in mind. This guide sets out the picture country by country, as reviewed in October 2026.
This is general information, not legal advice. Laws change, and individual circumstances matter. If you are making decisions about property, children or wills, speak to a qualified lawyer where you live.
The key distinction: relationships versus marriage
Polyamory describes relationships. Bigamy and polygamy describe marriages.
- Bigamy generally means marrying someone while still legally married to someone else.
- Polygamy generally means being married to more than one spouse at once, often within a religious or cultural tradition.
Dating two people, living with two partners, or belonging to a polycule does not involve any marriage, so it falls outside these laws. Trouble arises only if someone attempts a second legal marriage, or in some places a formal ceremony intended to create one.
United Kingdom
Polyamorous relationships are legal throughout the UK. In England and Wales, bigamy is a criminal offence under section 57 of the Offences Against the Person Act 1861, with equivalent offences in Scotland and Northern Ireland. Marriage and civil partnership are each limited to two people.
Cohabiting partners in England and Wales have far fewer automatic rights than spouses, whatever the number of people involved. Polyamorous households often rely on wills, declarations of trust for shared property, and lasting powers of attorney to protect each partner. Our United Kingdom guide covers local community context.
United States
Polyamory itself is legal in every state. Bigamy is illegal across the country, though penalties differ. Utah reduced bigamy between consenting adults from a felony to an infraction in 2020.
Some cities have moved toward recognising multi-partner households. Somerville, Massachusetts, adopted a domestic partnership ordinance in 2020 that can include more than two people. Cambridge followed in March 2021, and the town of Arlington approved a similar bylaw in April 2021. These local measures grant limited municipal rights, such as hospital visitation at town facilities, and do not change state marriage law.
Elsewhere, unmarried partners rely on contracts, wills, healthcare proxies and powers of attorney. See our United States guide for more.
Canada
Polyamorous relationships between unmarried adults are legal. The Criminal Code prohibits bigamy (section 290) and polygamy (section 293). In 2011, the Supreme Court of British Columbia upheld the polygamy provision in a reference case, interpreting it as aimed at multiple marriages rather than unmarried polyamorous relationships.
Canada has also seen notable family-law developments. British Columbia's Family Law Act allows a child to have more than two legal parents in some assisted reproduction arrangements. In 2018, a court in Newfoundland and Labrador recognised three unmarried adults in a polyamorous family as the legal parents of a child. Our Canada guide has more on local life.
Australia
Polyamorous relationships are legal across Australia. Bigamy is an offence under section 94 of the Marriage Act 1961.
Australian family law is unusual in one respect: the Family Law Act 1975 states that a de facto relationship can exist even if one of the people is legally married to someone else or is in another de facto relationship. That means overlapping relationships can carry legal consequences, particularly around property, if they break down. Partners in established households may want independent advice. See our Australia guide.
New Zealand
Polyamory is legal in New Zealand. Bigamy is an offence under section 205 of the Crimes Act 1961. The Property (Relationships) Act 1976 covers de facto relationships and includes provisions for situations in which relationships overlap, so polyamorous partners who share a home and finances should understand how it might apply to them. Our New Zealand guide has local context.
Ireland
Polyamorous relationships are legal in Ireland. Irish law still criminalises bigamy through the same Victorian statute that applies in England and Wales, a provision that survived independence. Marriage and civil partnership are each between two people.
The Civil Partnership and Certain Rights and Obligations of Cohabitants Act 2010 offers limited redress for cohabiting couples, and it was written with two-person relationships in mind. Polyamorous households often use wills and written agreements for clarity. See our Ireland guide.
Common misunderstandings
"Living with two partners is illegal." It is not. Sharing a home, a mortgage or a tenancy with more than one partner breaks no criminal law in any country covered here. Landlords may have rules about how many adults can live in a property, but those apply to any household.
"A commitment ceremony counts as marriage." In most places, a ceremony with no legal registration has no legal effect. Many polyamorous people hold handfastings or celebrations to mark their relationships, and these do not trigger bigamy laws. If you are already married, it is still sensible to check local rules before any ceremony that could be mistaken for a legal marriage.
"Polyamory can be used against me in a divorce." Family courts focus mostly on property, finances and children's welfare. Relationship structure can come up in custody disputes, which is one reason polyamorous parents benefit from early legal advice.
Practical protections for polyamorous families
Whatever country you live in, a few documents help protect partners who are not legally married:
- Wills. Without one, inheritance rules usually favour spouses and blood relatives.
- Powers of attorney. These let chosen partners make financial or medical decisions if you cannot.
- Healthcare directives. Written wishes help partners advocate for you in hospital.
- Property agreements. If several people contribute to a home, record who owns what.
- Parenting plans. Where children are involved, written agreements and legal advice reduce uncertainty.
Discrimination and workplace issues
Most anti-discrimination laws protect characteristics such as sex, sexual orientation and marital status, and few mention relationship structure explicitly. In practice, many polyamorous people choose carefully how open to be at work. If you face unfair treatment, an employment lawyer or union representative can advise on whether existing protections apply.
Talking about the law with family
Relatives sometimes worry that polyamory is illegal. A calm explanation helps: "We're not married to more than one person, so no marriage law applies. We're adults in consenting relationships, which is legal." Our guide on polyamory and family covers these conversations.
Frequently asked questions
Is it illegal to have more than one partner?
No. In the countries covered here, consenting adults may have more than one romantic or sexual partner. Laws restrict marrying more than one person, not dating or living together.
Can three people get married?
No. In the UK, US, Canada, Australia, New Zealand and Ireland, marriage is limited to two people. Some US cities offer multi-partner domestic partnerships with limited local rights.
Is polyamory the same as bigamy?
No. Bigamy means marrying someone while already married. Polyamory describes relationships that need not involve marriage at all.
Can a child have three legal parents?
In some places, yes. British Columbia allows more than two parents in certain cases, and a Newfoundland and Labrador court recognised three parents in 2018.
Do I need a lawyer if we live together as three?
It is wise to get advice about property, wills and powers of attorney, because most laws assume two-person couples.
When was this information last checked?
This guide was reviewed in October 2026. Laws change, so confirm details with a local lawyer.