Bigamy vs. Polygamy: The Differences

Bigamy and polygamy are words used to describe having multiple spouses. There are bigamy laws, but people can get around them depending on the circumstances. You’ve found the right article if you’re looking for a straightforward answer to the difference between bigamy and polygamy.

What Is Bigamy?

Bigamy is the act of entering into a marriage with one person while still legally married to another. A person practices bigamy when they have more than one spouse. In most cases, the person goes through a formal marriage ceremony to marry another person. Still, sometimes a person will live with another as if they were married without going through a ceremony or obtaining a license.

Examples of Bigamy:

  • A man has two wives (this is the most common form of bigamy)
  • A woman has two husbands
  • A woman marries a second husband before her first marriage is dissolved

It occurs when someone has married another person without legally ending their previous marriage. Both partners don’t need to be aware that their marriage is not legal for bigamy to occur. Many cases involve only one partner being aware of the bigamous situation.

It can involve one partner being oblivious that they are married sometimes! Typically, this occurs when a person already married neglects to get divorced before getting remarried to someone else.

What Is Polygamy?

The word polygamy comes from the Greek polygámía (from polýs, “many,” and gamós, “marriage”) and refers to the practice of having more than one spouse at the same time.

The most common form is polygyny: a marriage in which one man has multiple wives. In this case, the man is called a polygamist. Polyandry is the opposite of polygyny (women with many husbands), which occurs when a woman has multiple husbands simultaneously.

What Are the Differences Between Bigamy and Polygamy?

While bigamy and polygamy are often interchangeable, they are not the same. Bigamy is the act of marrying another person while still being married to a first spouse. Polygamy is the practice of having more than one spouse at one time. In other words, a polygamy is a form of bigamy, but not all bigamy is polygamy.

The differences are subtle but essential for understanding the law around the world. The critical distinction is that polygamy, unlike bigamy, does not necessarily involve formal or legally recognized marriages. Polygamy can be practiced in both monogamous and polygamous cultures.

In monogamous cultures, polygamy is usually only practiced by men and typically involves two wives at once (polygyny). In polygamous cultures, polygamy is traditionally practiced by both men and women and can involve multiple spouses (polyandry) or multiple spouses of each gender (group marriage).

Bigamy is typically defined as having two spouses at once — no more, no less — while polygamy can refer to having many spouses.

You might have violated laws against having multiple spouses if you were accused of bigamy. The potential penalties for this offense vary depending on where you live, though they can include fines or jail time. While most states allow only two spouses in a marriage, some recognize polygamous marriages as valid under certain circumstances or if they were entered into before laws banning it was passed.

Related Read: What is the difference between polyfidelity and polyamory and polyandry?

Is Bigamy Illegal in the U.S.?

In most countries, including the United States, bigamy is prohibited by law. The legal status of bigamy varies widely around the world. Some cultures consider it acceptable, while others do not allow it. In some places, bigamy can lead to imprisonment, and if you plan on emigrating to another country, it is essential to know if bigamy is a legal issue.

Bigamy is illegal in all 50 states and the District of Columbia. However, many states have exceptions for bigamy in certain circumstances. It is always a crime involving cohabitation with two people simultaneously, but some states permit bigamous marriages as long as the earlier marriage was legally dissolved.

In the U.S., the penalties for bigamy depend on which state you live in, but most states make it a misdemeanor offense punishable by up to $100,000 in fines and up to seven years in jail time.

What Is the Difference Between Bigamy and Adultery?

Even though adultery and bigamy involve the marriage of two people, they are not the same. Adultery is a form of infidelity in a relationship.

On the other hand, Bigamy is the act of being married to more than one person simultaneously.

Adultery occurs when a person is married to one individual and has sexual relations with another person who is not their spouse. Adultery can have serious consequences within a marriage. Even though it may be considered a wrongdoing, it is not illegal in all states. Bigamy, however, involves a person being legally married to two different people at the same time. This can be very confusing for all parties involved and can cause legal issues if one partner is unaware of the other partner’s spouse.

Adultery and bigamy are not the same things, but they can be similar if you consider that some people who commit adultery may do so by having more than one relationship at once or even marrying another person while already being married to someone else.

State Fine
California A fine of up to $10,000 or 1 year in jail. Also, the spouse of the bigamist may be charged $5,000 if they knew that the bigamist was married
Florida Five years in jail and a $5,000 fine
Idaho Three years in jail and a fine of $2,000
Massachusetts Up to 5 years in state prison and a fine of $500
Michigan Up to a year in prison and a fine of up to $500
Minnesota Up to 5 years in prison and a $10,000 fine
Mississippi Up to 10 years in prison. Medical licenses can be revoked, and cannot be appointed to public office
Montana Six months in prison or a $500 fine or both
New Mexico 2 to 7 years in prison
New York 3 to 4 years in prison
Oklahoma Five years in jail
Oregon Up to 5 years and a $100,000 fine
South Carolina Up to 5 years and at least a $500 fine
Texas 2 to 10 years in prison and a fine of $10,000
Vermont A sentence of not more than five years of prison

Why Is Bigamy Illegal?

Knowing that they have not legally divorced from a living spouse, a person who marries another person is guilty of bigamy, regardless of whether the second marriage is solemnized.

The law around bigamy was simple: children born after two people married to have a legitimate father and mother. If two people were married before contracting another marriage, then it was possible that the child could be fathered by someone other than the supposed father.

Consequently, children might be born with parents who were not their parents. This situation would lead to a breakdown in family ties that could easily lead to social chaos.

In modern times, there are many other reasons why bigamy is illegal:

  • It makes it difficult for authorities to keep track of people who are considered “married.”
  • It can be used as part of an immigration scam; one or both parties have entered into the marriage primarily to obtain citizenship for one party.

Bigamy is illegal because it increases the likelihood of paternity fraud and child support disputes. If multiple people claim to be the father of a child, it puts both the mother and the child at risk of financial hardship if paternity is not established before the mother receives welfare or food stamps.

Because bigamy is illegal in all states and countries, a bigamous marriage can’t be legally valid. However, some couples mistakenly believe they can enter into a second marriage without getting divorced from their first spouse. So, if you are going through a divorce or annulment, speak with a family law attorney about your rights and options under state law.

Final Thoughts

Bigamy is a grave crime, and it should never be taken lightly. It is defined as the act of being married to more than one person at the same time, and it is illegal almost everywhere in the United States. Committing bigamy carries severe penalties, ranging from fines to prison time, depending on where you live. Aside from being a crime, bigamy can be incredibly damaging to you and your loved ones.


  • Shepard, L. D. (2012). The impact of polygamy on Women’s Mental Health: A Systematic Review. Epidemiology and Psychiatric Sciences, 22(1), 47–62.
  • BOVE, R. M., VALA-HAYNES, E. M. I. L. Y., & VALEGGIA, C. L. A. U. D. I. A. (2013). Polygyny and women’s health in rural Mali. Journal of Biosocial Science, 46(1), 66–89.
  • Corbett, J. (2021, July 6). Bigamy law: Charges, penalties and defenses. LegalMatch Law Library. Retrieved April 29, 2022, from

Hi, I am Happy. I'm a professional writer and psychology enthusiast. I love to read and write about human behaviors, the mind, mental health-related topics, and more.