Polyamory vs polygamy: key differences explained
Polyamory means having more than one loving relationship at the same time, with everyone's knowledge and consent, and it does not involve marriage. Polygamy means being married to more than one spouse at once. The two words sound alike and are often confused, but they differ in consent, gender, marriage and law.
This guide sets the two side by side in plain language, explains where polygyny and polyandry fit, and covers what the law says in the countries we write about. For a country-by-country legal summary, see our guide to whether polyamory is legal.
The short answer
- Polyamory is about relationships. It can involve any genders, any number of partners, and people who are married, unmarried or single. Its defining feature is informed consent from everyone involved.
- Polygamy is about marriage. It describes one person who has more than one spouse at the same time, usually within a religious, cultural or legal framework that recognises those marriages.
A polyamorous person might be married to one partner and date another, live with two unmarried partners, or have no spouse at all. A polygamous person, by definition, has at least two spouses.
Where the words come from
Polygamy comes from Greek roots meaning "many marriages", and it has been used in English for centuries. Polyamory is much newer. It joins the Greek "poly" (many) with the Latin "amor" (love), and it came into wider use in the early 1990s. Our guide to what polyamory means covers its history in more detail.
Polygyny, polyandry and polygamy
Polygamy is an umbrella term with two main forms:
- Polygyny: one man married to more than one wife. This is by far the most common form of polygamy worldwide, and it is what most people picture when they hear the word.
- Polyandry: one woman married to more than one husband. It is much rarer and has been documented historically in a small number of communities, including some in the Himalayan region, where brothers sometimes shared one wife.
A third, rarer arrangement is sometimes called group marriage, where several people are all married to one another. It has no legal recognition in the countries we cover.
Polyamory has no built-in gender pattern. A woman can have two boyfriends, a man can have a husband and a girlfriend, a non-binary person can have three partners of different genders, and any partner can have other partners too.
Key differences at a glance
| Polyamory | Polygamy | |
|---|---|---|
| What it describes | Loving relationships with more than one person | Marriage to more than one spouse |
| Marriage | Not required; partners may be married, unmarried or both | Required by definition |
| Gender pattern | Any genders and combinations | Usually one man with several wives (polygyny); rarely one woman with several husbands (polyandry) |
| Who can have other partners | Any partner, depending on agreements | Often only the person with several spouses |
| Consent | Informed consent from everyone is the core principle | Varies by tradition; not always freely given |
| Legal status in UK, US, Canada, Australia, NZ, Ireland | Relationships are legal | Multiple marriages are not recognised; bigamy is an offence |
Consent and equality
Consent is the clearest dividing line. In polyamory, every partner knows about the others and has agreed to the arrangement. Each person also keeps the right to change their mind, renegotiate or leave. Polyamorous agreements are usually built from the ground up by the people in them, rather than inherited from a tradition.
Polygamy is practised in many different ways across the world, and it would be unfair to say all polygamous marriages lack consent. But in many traditions, the structure is set by religious or cultural rules rather than negotiated by the spouses, and it is often asymmetric: the husband may take additional wives, while the wives may not take additional husbands. Human rights bodies have raised concerns about polygyny where it is linked with child marriage or unequal rights for women.
Marriage and the law
In the six countries we cover, the United Kingdom, the United States, Canada, Australia, New Zealand and Ireland, marriage is limited to two people. Bigamy, marrying someone while still married to someone else, is an offence in each of them. Canada's Criminal Code also contains a separate polygamy offence in section 293, and in 2011 the Supreme Court of British Columbia upheld that provision while interpreting it as aimed at multiple marriages rather than unmarried polyamorous relationships.
Polyamory itself is legal in all six countries, because dating or living with more than one partner involves no second marriage. A few local governments in the United States, starting with Somerville, Massachusetts, in 2020, have adopted domestic partnership rules that can include more than two people. These grant limited local rights and do not change marriage law. Our legal guide covers the details, including wills and other documents that help polyamorous households.
Elsewhere in the world, polygyny is legally recognised in a number of countries, mostly in parts of Africa, the Middle East and Asia, often under religious or customary family law. Polyandry has very little legal recognition anywhere today.
Why the confusion matters
Mixing the two words up causes real problems for polyamorous people. Relatives may assume that polyamory means a religious arrangement with unequal power, or that it is illegal. Employers and officials may worry about something that is entirely lawful. In dating, someone may assume that a polyamorous man wants several wives, when he is simply open to more than one relationship and expects his partners to have the same freedom.
When the subject comes up, a short explanation usually helps: "Polygamy is about having more than one spouse. Polyamory is about honest relationships with more than one person, and nobody has to be married." Our guide to polyamory myths covers other common misunderstandings.
Can someone be both?
It is possible for a person in a polygamous marriage to describe their family as polyamorous, particularly in places where multiple marriages are legal and all spouses chose the arrangement freely. It is also possible for a polyamorous person to hold commitment ceremonies with more than one partner, which some people loosely call polygamy. In the countries we cover, though, such ceremonies have no legal effect, and anyone who is already married should check local rules before any ceremony that could be mistaken for a legal marriage.
How polyamory compares with other terms
Polygamy is not the only word that gets confused with polyamory. An open relationship usually means a couple who allow outside sex but keep romance within the couple. Swinging usually means couples who have sex with other couples or singles, often socially and together. Our guide to polyamory vs open relationships compares these, and the polyamory glossary defines the rest.
Dating with clarity
If you are polyamorous, saying so clearly on your profile saves time and avoids the polygamy mix-up. Mention your current partners, what you are looking for and how your relationships work. On Polyamory Contacts, everyone browsing already understands polyamory, so conversations can start from shared ground rather than a definition.
Frequently asked questions
What is the main difference between polyamory and polygamy?
Polyamory is about consensual loving relationships with more than one person and does not require marriage. Polygamy is about being married to more than one spouse at the same time.
Is polyamory a form of polygamy?
No. Polygamy requires multiple marriages. Most polyamorous people have at most one legal spouse, and many have none.
What is polyandry?
Polyandry is a form of polygamy in which one woman is married to more than one husband. It is much rarer than polygyny, where one man has several wives.
Is polyamory legal?
Yes, in the UK, US, Canada, Australia, New Zealand and Ireland. What these countries restrict is marriage to more than one person, not relationships.
Is polygamy legal anywhere?
Polygyny is legally recognised in a number of countries, mostly in parts of Africa, the Middle East and Asia. It is not recognised in the six countries we cover.
Can a polyamorous person marry more than one partner?
Not legally in the countries we cover. Some hold commitment ceremonies with no legal effect and use wills and agreements to protect each partner.