Polygamy in Canada: What the Law Actually Says (and Why It Matters)
By Marcus M. Sixta, Sr. Family Lawyer, Registered Family Mediator, and Arbitrator
The definition of “family” in Canada continues to evolve. We’re seeing more discussion around non-traditional relationships—particularly polyamory—but there is still a lot of confusion about what is legally permitted and what is not.
One of the most common misconceptions I hear is that polygamy and polyamory are treated the same under Canadian law. They are not. One is a criminal offence under the Criminal Code.
That distinction is important. Not just from a criminal law perspective, but also for family law rights and obligations.
Polygamy Is Illegal in Canada
Let’s start with the clear rule: polygamy is a criminal offence in Canada.
Polygamy refers to being married to more than one person at the same time. This includes:
- One person with multiple spouses (polygyny or polyandry).
- Group marriages involving multiple spouses.
All forms of polygamy are prohibited under the Criminal Code, and the offence carries a potential penalty of up to five years in prison.
This prohibition has been tested in the courts. In a 2011 decision, the BC supreme court confirmed that Canada’s ban on polygamy is constitutional and consistent with the Charter of Rights and Freedoms.
While prosecutions have historically been rare, the law is very much alive. The 2017 convictions of religious leaders in Bountiful, BC marked the first successful polygamy prosecutions in over a century. One reason for so few prosecutions is that proving polygamy can be difficult since many polygamous unions are not legally registered, but rather religious marriages that are “off the books”.
You Can’t Legally Marry More Than One Person
From a practical standpoint, the system is designed to prevent polygamy before it happens.
There is a sharing of provincial and federal authority over marriages. The federal government regulates who can get married, including legal capacity, age, consent, and prohibited relationships. The federal government also governs divorce and its legal consequences.
The provincial government regulates the solemnization of marriage, including issuing marriage licences, authorized officiants, ceremony requirements, and registration.
When applying for a marriage licence in Canada, you must certify that you are:
- Never married.
- Divorced.
- Or, widowed.
However, the certification process is based on the applicant being honest, and this leaves it open to abuse by bad actors.
There is little oversight by the provincial governments and the only province in which a marriage officiant is required to determine if someone is already married is Quebec. Moreover, provinces do not share databases with each other, making it difficult to determine whether someone is already married in another province.
This lack of oversight has led to abuse of the system, as highlighted in a recent CTV News investigation involving a man who allegedly had simultaneous marriages across Canada and the United States: CTV Multiple wives story.
While the threat of criminal prosecution is a deterrent, it’s minimized by the fact that criminal prosecution of polygamy is extremely rare.
However, if someone attempts to remarry while still legally married, the second marriage is not legally valid and can be annulled. That said, annulments can create additional legal issues, particularly when it comes to family property division and spousal support, which vary across provinces.
What Happens If Someone Tries Anyway?
If a person enters into a second marriage while still married, the second marriage is not legally valid.
In these situations, the appropriate legal remedy is typically an annulment, which is a declaration that the marriage never legally existed.
However, and this is important, even if a marriage is annulled, parties may still have rights and obligations under family law legislation, including claims for:
- Property and debts.
- Spousal support.
- Or child support
In other words, the relationship may still have legal consequences, even if the marriage itself was invalid.
Polyamory Is Not Illegal
Now, for the nuance: polyamory is legal in Canada.
Polyamory generally refers to consensual, multi-partner relationships where:
- All parties are aware of each other.
- All relationships are based on consent and openness.
The courts have explicitly distinguished polyamory from polygamy. The criminal prohibition is specifically aimed at multiple marriages, not multi-partner relationships.
This means:
- You can be in multiple romantic relationships.
- You can cohabit with multiple partners.
- You can structure your family in non-traditional ways.
But you cannot be married to more than one person at the same time.
Where Family Law Gets Complicated
Even though polygamy is illegal, family law has evolved in ways that recognize the realities of modern relationships. However, it’s important to note that how this plays out is different from province to province.
British Columbia: Flexible but Complex
BC’s Family Law Act is relatively flexible in how it defines “spouse”.
A person can qualify as a spouse if they:
- Are married.
- Or have lived in a marriage-like relationship for at least two years (or less if they have a child).
Because of this structure, it is possible for someone to have more than one legally recognized spouse at the same time. For example, a separated married spouse and a new common-law partner.
This creates real legal consequences:
- Multiple potential spousal support claims.
- Overlapping property rights.
- Competing legal obligations.
BC law has also adapted to modern parenting structures. The BC courts have determined that a child can have multiple parents even where a child is conceived from sexual intercourse. This change forced the government to allow the registration of more than two parents on the birth records of a child. Also, in one BC case, a multi-parent agreement created in a polyamorous relationship was upheld.
Alberta: More Restrictive on “Multiple Partners”
Alberta takes a more structured and, in some ways, more restrictive approach.
Instead of “common-law”, Alberta uses the concept of an adult interdependent partner (AIP).
Under section 3(1) of the Adult Interdependent Relationships Act, an AIP is created when two people:
- Live together in a relationship of interdependence for at least three years.
- Have a child together.
- Or sign an adult interdependent partner agreement.
But in Alberta, you cannot have more than one AIP at the same time. Also, a married person cannot become an AIP while living with their spouse.
Under Alberta’s Family Law Act, a child can only have up to two legal parents, even if the child was conceived through assisted reproduction. However, the courts can appoint more than two people as a child’s guardians.
The Takeaway
The law in Canada draws a very clear line:
- Polygamy (multiple marriages) → Illegal and criminal
- Polyamory (multiple relationships) → legal, but complex
From a family law perspective, even when a relationship structure falls outside traditional norms, the legal consequences can still be significant.
Property, support, parenting, and estate issues don’t disappear just because a relationship isn’t conventional—they often become more complicated.
As family structures continue to evolve, the law is slowly adapting, but not always in a clean or predictable way.
If you are in or considering a non-traditional relationship, the most important thing you can do is get clarity early:
- What are your rights?
- What are your obligations?
- How can you structure things to avoid future conflict?
Because when things break down, the legal system will still step in and it may not align with how you thought your relationship worked.
If you have questions about how BC or Alberta family law applies to your relationship, Crossroads Law can help. Contact us for a free 20-minute consultation to understand your rights and obligations.
The information contained in this blog is not legal advice and should not be construed as legal advice on any subject. The information provided in this blog is for informational purposes only.
