“At-Fault” Divorce in Canada: What It Is, and When It Matters

Recently, we wrote about what it means to get a “no-fault” divorce in Canada.

Most divorces proceed on a no-fault basis because it’s usually the simplest, fastest, and most cost-efficient way to go.

But did you know that an “at-fault” divorce is also available? This route applies to situations where misconduct by a spouse is what causes the marital breakdown. While it’s less commonly used in Canada, understanding what is at-fault divorce and how it works can be important, especially if it might apply to you.

Let’s unpack what happens in a fault divorce, and when it might matter.

What Are the Grounds for At-Fault Divorce in Canada?

First things first: In order to get a divorce in Canada, you have to show there has been a “breakdown of the marriage” as that term is defined in the Divorce Act. This concept includes only three possible grounds—one being no-fault and the other two forming the basis for at-fault divorce in Canada. They are:

• Living separate and apart for at least one year (a no-fault ground);
• Adultery committed since the wedding (a fault-based divorce ground); or
• Mental or physical cruelty that renders continued cohabitation intolerable (also a fault-based divorce ground).

Proving the Misconduct

These last two grounds hinge on spousal misconduct. But if you want to rely on either one as the basis for a fault-based divorce, it’s not enough to merely accuse your spouse. You must provide clear, convincing evidence in court.

Adultery

To claim adultery:

• You must prove your spouse had a sexual relationship with someone else during the marriage.
• The adultery must have occurred before you applied for the divorce.
• Just to be clear: You can’t file based on your own adultery – it must be your spouse’s.

In an interesting 2005 decision, The Supreme Court in B.C. dealt with whether same-sex sexual activity qualifies as “adultery” for divorce purposes. In P. (S.E.) v. P. (D.D.), 2005 BCSC 1290, and it involved a husband and wife who had been married almost 20 years.  The wife sought a divorce after the husband admitted that he had voluntarily had sex with another man.

In lengthy reasons, the court considered (among other things) the history of the Divorce Act and the common-law definition of “adultery”; it also examined the societal and legal impact of the successful challenges to same-sex marriage under the Charter, that had been brought around the same time.

In the end, the court affirmed the principle that same-sex sexual activity can indeed constitute adultery for the purposes of the Divorce Act, explaining:

“Individuals of the same sex can now marry and divorce and the common law would be anomalous if those same-sex spouses were not bound by the same legal and social constraints against extra-marital sexual relationships that apply to heterosexual spouses.”

We turn next to the question of the definition of what sexual acts constitute adultery and whether this court should attempt to define adultery.

At-Fault Divorce in Canada: What is the Definition of Adultery

The traditional definition of adultery included the requirement that the sexual activity be intercourse. Because sexual relations might involve no penetration at all, this requirement could serve to deny a divorce to a man or a woman whose partner is having a sexual affair with a person of the same sex.  However, the uncertainty about precisely what would constitute adultery in a same-sex relationship is not a reasonable basis for denying spouses the ability to divorce on the basis of same-sex sexual activity.

In the modern understanding of marriage, the wrong for which the petitioner seeks redress is something akin to violation of the marital bond.  Viewed from this perspective, the heterosexual nature of the sexual acts is not determinative.  Intimate sexual activity outside of marriage may represent a violation of the marital bond and be devastating to the spouse and the marital bond regardless of the specific nature of the sexual act performed.

On the facts of the case, the husband’s confession that he had sex with another man outside the marriage was sufficient to prove adultery, and the wife’s request for an at-fault divorce was granted accordingly.

Cruelty

To prove cruelty as the basis for an at-fault divorce in Canada:

• You must show your spouse’s behaviour was physically or mentally abusive to the point that living together became intolerable.
• The conduct must go beyond ordinary marital disputes; it has to be serious in nature.
• There must be more than mere animosity between you and your spouse. As the court explained in a recent case called S.X. v. A.B., 2024 ONSC 1260 at para. 9:

The law is clear that in order to make a finding of cruelty, there must be more than dislike between the spouses. It is a subjective inquiry; each case requires a very contextual and specific analysis. The intention of the respondent is not the issue; a person may be cruel and cause harm to another due to their words and actions without even realizing it.

For an example of how to get a divorce under this particular at-fault ground, the recent decision in P.S.X. v. A.B., 2024 ONSC 1260 is worth noting. There, the court was asked to consider a husband’s request for a divorce based on his claims that, within a mere month of their wedding, his new wife had been intolerably cruel to him.

The husband gave evidence that the wife had “mentally and emotionally harassed [him] and often threw [his] belongings out of the house”.  Police reports backed this up, and included statements from the husband that he feared for his safety due to the wife’s verbal and physical conduct toward him. During the final incident in 2023, the police helped the husband leave the marital home with his belongings – never to return.

Fault-based Divorce Ground: Uncontradicted Harm

Although the court accepted the evidence supplied by the husband, it paused when reviewing two the affidavits filed by one of his friends, and by a family member.  These were ruled inadmissible as hearsay, since they were not based on those parties’ personal observations. Still, the affidavits could be admitted to establish the husband’s state of “acute distress”, since they provided “direct observations of the [husband’s] ongoing manifestations of psychological pain and stress following his marriage and since his separation from the [wife].”

After ruling that the wife’s post-marriage behaviour caused the husband “significant psychological distress” to the point that continued cohabitation with her was intolerable, the court made an important legal point:  It did not have to decide whether the wife intended that outcome. As the court put it:

“She may have been indifferent to the effects of her behaviour on him. In either event, the subjective harm to her husband is uncontradicted.”

In the end, the court concluded that the wife’s treatment of her husband caused “grave and weighty” harm, which was sufficient to establish that their relationship had broken down based on cruelty. It granted the husband a divorce.

Does Getting an At-Fault Divorce Boost My Financial and Parenting Rights?

If you’re considering an at-fault divorce in Canada, you might assume that adultery or cruelty by your spouse will give you a legal advantage when it comes to property or parenting.

Not necessarily.

While what is at-fault divorce can affect the grounds on which your marriage ends, it doesn’t usually influence financial or parenting outcomes. The Divorce Act governs the legal end of the marriage – but not issues like property division, parenting, or support. Those are usually governed by provincial legislation such as Ontario’s Family Law Act. Even proven misconduct won’t automatically strip your spouse of financial or parenting rights, since courts must make those assessments independently, and in line with the dictated principles that unpin their legislated mandates.

That said, egregious behaviour – particularly family violence – can be relevant. For example, cruelty may justify the court deciding to limit or supervise your spouse’s parenting time, if this is found to be in your child’s best interests.

The Pros and Cons of Filing for At-Fault Divorce

“At-fault” divorce can sometimes feel like the emotionally appropriate option—especially if your partner’s behaviour was truly harmful to you. But choosing this route comes with important legal and practical implications. Here’s what to consider:

The Pros

• No Waiting Period. If you can successfully prove adultery or cruelty, you don’t have to wait out the one-year separation period. This can speed up the process in some cases—though only if the evidence is clear and uncontested.
• Validation and Accountability. For some, pursuing an at-fault divorce feels like a way to affirm that the other spouse’s wrongdoing caused the end of the marriage. It may provide a sense of justice or closure, especially where abuse, infidelity, or other betrayal was involved.

The Cons

• Harder to Prove. Adultery or cruelty must be proven to the court with clear evidence—witness statements, documentation, or even admissions. This can be hard to do, especially if the spouse denies the conduct.
• Public and Emotional Exposure. Filing for at-fault divorce in Canada turns private conduct into a legal issue. Allegations are documented in court filings and may become part of the public record. For many, reliving painful experiences in open court can make healing harder.
• More Expensive and Time-Consuming. Contested fault-based divorces can quickly become expensive. If your spouse disputes the allegations, you may need a trial to resolve the issue. That adds time, legal fees, and emotional strain.

So, Should You File for At-Fault Divorce?

In most cases, the answer is: probably not—unless there’s a compelling reason to do so. As mentioned, the no-fault route is usually faster, more private, and less costly.

That said, there are cases where filing an at-fault divorce on the basis of cruelty (for example, in family violence situations) may be strategically useful, or else emotionally meaningful. If you’re unsure, feel free to give our offices a call; we can help guide you through your options and help you decide what’s right in your situation.