- Canada operates a no-fault divorce system — adultery is technically one of three legal grounds for divorce, but it generally does not affect anything else.
- Section 15.2(5) of the Divorce Act explicitly states a court “shall not take into consideration any misconduct of a spouse in relation to the marriage” when making a spousal support order.
- Adultery generally has no effect on property division under Ontario's equalization regime, which is fault-neutral.
- Adultery generally has no effect on parenting decisions unless the underlying conduct directly affected the children or the person's ability to parent.
- While the misconduct itself is irrelevant, the consequences of certain misconduct — such as abuse affecting a spouse's ability to become self-sufficient — can still be relevant to support.
- Almost all Ontario divorces proceed on the one-year separation ground instead of adultery, since it requires no proof of fault.
The Short Answer
Almost never. Canada operates a no-fault divorce system, and this shapes nearly everything about how adultery is actually treated legally. While adultery is technically one of three legal grounds for divorce, it generally has no bearing on property division, spousal support, or parenting decisions.
Adultery as a Ground for Divorce
The Divorce Act recognizes three grounds for divorce: one year of separation, adultery, and cruelty. In practice, the overwhelming majority of Ontario divorces proceed on the separation ground, since it requires no proof of fault — simply living separate and apart for a year. Proving adultery, by contrast, can be uncomfortable, costly, and is rarely necessary.
Does Adultery Affect Property Division?
No. Ontario's equalization of net family property regime is fault-neutral — it is based on each spouse's financial contributions and net worth at separation, not on marital conduct.
See our guide on how property is divided in an Ontario divorce for the full equalization formula.
Does Adultery Affect Spousal Support?
Section 15.2(5) of the Divorce Act states that a court “shall not take into consideration any misconduct of a spouse in relation to the marriage” when making a spousal support order. Adultery, on its own, simply is not a legally relevant factor in determining entitlement or amount.
There is an important distinction, however: while the misconduct itself is irrelevant, the consequences of certain misconduct can matter. If abuse (a separate category from adultery) left a spouse unable to work, that impact on their ability to become self-sufficient is relevant to support — not as punishment for the misconduct, but because of its real financial consequence.
Does Adultery Affect Custody or Parenting?
Generally, no. Ontario's best-interests-of-the-child standard focuses on parenting capacity and the child's needs, not on marital fidelity. An affair, by itself, is not treated as a reflection of someone's ability to parent.
A parent had an affair that contributed to the marriage ending. In parenting discussions, courts focus on that parent's actual relationship with the children, their caregiving history, and their ability to meet the children's needs — not on the affair itself, unless it somehow directly involved or affected the children.
When Might Conduct Actually Matter?
- Consequences of misconduct affecting self-sufficiency — such as abuse impairing someone's ability to work — can be relevant to spousal support, even though the misconduct itself is not directly considered.
- Truly exceptional, “unconscionable” circumstances can, in narrow cases, justify departing from the standard equalization formula — a very high bar, not met by ordinary marital misconduct.
- Conduct directly affecting the children, or a parent's demonstrated ability to safely care for them, remains relevant to parenting decisions.
Common Myths
Myth: “If my spouse cheated, I'll get more in the settlement.”
False. Ontario's no-fault system means infidelity, on its own, does not increase or decrease a property or support outcome.
Myth: “Proving adultery will speed up my divorce.”
Not necessarily — proving adultery can actually be more time-consuming and costly than simply waiting out the one-year separation period, which requires no proof of fault at all.
Myth: “A parent who had an affair is automatically seen as less fit.”
False. Parenting decisions focus on parenting capacity and the child's best interests, not marital conduct unrelated to caregiving.
Navigating a divorce involving infidelity and want a clear-eyed legal perspective? Call our Toronto family lawyers at 416-274-2222 for a free consultation.
Frequently Asked Questions
No. Ontario's equalization of net family property regime is fault-neutral — it divides property based on each spouse's financial contributions and net worth at separation, not on who was "at fault" for the relationship ending, including infidelity.
Generally, no. Section 15.2(5) of the Divorce Act explicitly states that a court shall not take into consideration any misconduct of a spouse in relation to the marriage when making a spousal support order. Adultery, on its own, is not a factor in determining entitlement or amount.
Yes, technically — the Divorce Act recognizes three grounds: one year of separation, adultery, and cruelty. However, adultery is rarely used in practice, since it requires proving the adultery occurred, which is often uncomfortable, costly, and unnecessary given that the one-year separation ground requires no proof of fault at all.
Generally, no, unless the underlying conduct directly affected the children or genuinely impacts a parent's ability to care for them. An affair, on its own, is not treated as a reflection of parenting ability under Ontario's best-interests-of-the-child standard.
For support, the relevant factors are entitlement, income, the length of the relationship, and need — not fault. For property, it's each spouse's financial position and contributions. For parenting, it's the best interests of the child, focused on parenting capacity and the child's needs.
Yes, in narrow circumstances. While misconduct itself (like adultery) is not a factor, the consequences of certain misconduct can be relevant — for example, if abuse left a spouse unable to work, that impact on their ability to become self-sufficient can be relevant to spousal support, even though the abuse itself is not being "punished" through the support award.
In very limited, exceptional circumstances, a court can depart from the standard equalization calculation if applying it would be "unconscionable" given the specific circumstances — but this is a high legal bar, reserved for truly exceptional situations, not ordinary marital misconduct like an affair.
In some rare cases, a spouse may not want to wait out the full one-year separation period and may have provable grounds for adultery or cruelty that allow the divorce to proceed sooner — though even then, it typically does not change the outcome of property, support, or parenting issues.
It can be relevant to parenting decisions if it genuinely affects the children or a parent's capacity to care for them safely, and it can be relevant to support where it has a real, provable financial or functional consequence — but ordinary marital misconduct like an affair, on its own, generally is not a legal factor.
It rarely changes the outcome of a standard divorce, but if you believe the conduct had real consequences relevant to parenting or a spouse's ability to become self-sufficient, documenting the actual impact — not just the conduct itself — is what would be legally relevant, and worth discussing with a lawyer.