Adultery as a Legal Ground for Divorce
Under the federal Divorce Act, there are three recognized grounds for divorce: living separate and apart for at least one year, adultery, or cruelty that makes continued cohabitation intolerable. Adultery is a real, recognized ground — a spouse can apply for divorce based on it without waiting out a full year of separation, provided the adultery can be established to the court's satisfaction.
In practice, this means a spouse who believes their partner has committed adultery doesn't have to wait a year to start a divorce application. That said, relying on adultery as the stated ground generally means being prepared to establish it, which is where the practical difficulties tend to begin.
Why Almost No One Actually Uses It
Despite being available, adultery is rarely the ground relied on in practice. The one-year separation ground is generally simpler: it doesn't require proving anything about why the marriage ended, only that the spouses have been living separate and apart for a year (and in many cases, an application can be started before the year is up, with the divorce granted once it's complete).
Relying on adultery as a ground can also introduce more conflict into a process that many separating spouses would rather keep as low-conflict as possible, since it generally requires the applicant to make and support an allegation the other spouse may dispute. For most couples, waiting out the separation period is seen as the more straightforward and less adversarial path, even where adultery may have played a role in the breakdown of the marriage.
Does It Affect Property, Support or Parenting?
Generally, no. Ontario's approach to dividing property after a marriage ends, under the Family Law Act's equalization scheme, is not fault-based — it focuses on sharing the growth in net worth during the marriage, not on who was "responsible" for the separation. See our guide to property division in Ontario for how that generally works.
Spousal support is also generally assessed based on need, compensation for roles taken during the relationship, or an agreement — not on fault. Similarly, parenting arrangements are generally guided by the best interests of the child, which focuses on the child's needs and each parent's ability to meet them, not on marital conduct, except in the rare case where specific conduct is directly relevant to a parent's ability to care for a child.
Frequently Asked Questions
Is adultery illegal in Canada?
No. Adultery is not a crime in Canada. It's relevant in family law only as one of the three legal grounds a spouse can rely on to apply for divorce.
Can I get divorced immediately if my spouse committed adultery?
You don't have to wait out the full one-year separation period if you rely on adultery as your ground, but you generally need to be able to establish it to the court's satisfaction, which can add its own complications.
Does adultery affect how much spousal support I'll get?
Generally, no. Spousal support in Ontario is generally assessed based on entitlement, need, and the length and nature of the relationship, not on which spouse was unfaithful.
Will adultery affect custody or parenting time?
Generally not directly. Parenting arrangements are generally based on the best interests of the child, not on a parent's conduct in the marriage, unless that conduct is directly relevant to parenting ability or the child's safety.
Do I need proof to use adultery as a ground for divorce?
Generally, yes — the party relying on it needs to be able to establish it to the court. This is part of why most people instead rely on the one-year separation ground, which doesn't require proving fault.