Polygamy

Also: polygyny, polyandry, plural marriage

Marriage to more than one spouse at once — a marital and often religious institution. It is distinct from polyamory, with which it is frequently confused: polygamy is about marriage, polyamory is about loving relationships.

1 min read · Reviewed 2026-05-24

Polygamy means being married to more than one person simultaneously. It usually refers to a formal, often religiously-sanctioned institution, and it most commonly takes the form of polygyny (one husband, multiple wives); the rarer reverse is polyandry (one wife, multiple husbands). Polygamy is illegal in most Western countries as a marital status, and it is historically structured around a single central spouse to whom the others are married, rather than a web of mutual relationships.

Polygamy is the term polyamory gets confused with most often, and the distinction matters. Polyamory is about loving, romantic relationships and carries no requirement of marriage; it is typically egalitarian or at least mutually-negotiated, and is not tied to any religion. Polygamy is about marriage and is frequently embedded in patriarchal or religious frameworks where the wives are not partnered with each other. 'Poly' as a prefix sits in both words but they describe different things.

The confusion is worth clearing up precisely because critics sometimes conflate the two to import polygamy's associations (coercion, patriarchy, religious control) onto polyamory. Most polyamorous people are not seeking plural marriage and would not recognise their relationships in the polygamy frame.

Where this term fits in the wider picture

Ethical non-monogamy is a network of overlapping practices, identities, and structures — and Polygamy connects to several of them. The neighbouring terms below show how this one sits alongside the rest of the vocabulary practitioners actually use; the guide at the end is the longer-form treatment of the same territory.

Closely-related vocabulary

Polyamory
The practice of, or willingness to engage in, multiple loving romantic relationships, with the knowledge and consent of everyone involved.
Polyfidelity
A relationship structure with three or more committed partners who are not open to additional partners outside the group.
Group marriage
A relationship in which three or more people consider themselves married to one another as a unit. Legally unrecognised everywhere in the West, but practised socially and symbolically by some polyfidelitous families.
Ethical non-monogamy
An umbrella term for relationship structures in which everyone involved knows about, and consents to, the participants having more than one romantic or sexual connection.
Consensual non-monogamy (CNM)
The umbrella term for any relationship structure in which all partners knowingly agree to romantic or sexual connections with more than one person. Used interchangeably with ethical non-monogamy.

Continue reading

The longer treatment of this territory is in the guide What is ethical non-monogamy? A clear primer for adults thinking it through — An honest, plain-language introduction to ethical non-monogamy — what it is, what it isn't, the configurations it covers, and the questions it asks of you.

New to ethical non-monogamy? Start with the glossary for vocabulary, the structures index for the named relationship configurations practitioners actually use, and the guides for longer-form treatment of the common questions.