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Why Almost No One Uses Adultery or Cruelty as Grounds for Divorce in Ontario

Ontario law allows adultery and cruelty as grounds for divorce, but almost no one uses them. Here's why living separate and apart is the practical default.

Family Law5 min readTSLBy the Treadstone Law team · OntarioUpdated 2026-07
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Key takeaways
  • Under the Divorce Act, a marriage has broken down — the legal requirement for divorce — if the spouses have: - Lived separate and apart for the required minimum period, which is the…
  • Relying on adultery or cruelty means you're not just asserting the marriage broke down — you're asking the court to make a finding of fault against your spouse, based on evidence.
  • Choosing a fault-based ground doesn't give you a stronger position on money or children — it just changes how you prove the marriage is over.

Ontario's Divorce Act technically gives you three ways to prove a marriage has broken down: living separate and apart, adultery, or cruelty. In practice, nearly every divorce in the province relies on the first one. That's not an accident, and it's not because adultery or cruelty never happen — it's because proving either one in court is harder, slower, and more expensive than simply relying on separation.

If you're wondering whether naming fault might get you divorced faster, or somehow improve your outcome, it's worth understanding why experienced family lawyers so rarely recommend it.

The Three Legal Grounds, Briefly

Under the Divorce Act, a marriage has broken down — the legal requirement for divorce — if the spouses have:

Any one of these is legally sufficient on its own. They are not equally practical.

Why Adultery and Cruelty Are Hard to Prove

Relying on adultery or cruelty means you're not just asserting the marriage broke down — you're asking the court to make a finding of fault against your spouse, based on evidence. In practice, that typically means:

It Doesn't Change What You Actually Get

This is the part that surprises people: the ground you use to prove marriage breakdown doesn't affect how property is divided, whether spousal support is paid, or what parenting arrangements look like. Those issues are decided under their own separate legal tests, not on which spouse was "at fault" for the marriage ending. Choosing a fault-based ground doesn't give you a stronger position on money or children — it just changes how you prove the marriage is over.

Why Separation Wins by Default

  1. No one has to be blamed. Separation only requires showing you've been living apart — it doesn't require proving anyone did anything wrong.
  2. It's far less likely to be contested. A spouse who might dispute an adultery or cruelty allegation usually has nothing to dispute about the plain fact that you've been separated.
  3. It keeps the process calmer. Avoiding fault-finding tends to make the rest of the process — negotiating support or parenting arrangements — less adversarial too.
  4. It's the well-worn path. Court staff, forms, and procedure are all built around separation being the default; it's simply the smoother route through the system.

What About Family Violence?

It's worth separating two different things that sometimes get conflated. Family violence is a serious, named factor in how courts decide parenting arrangements — it's expressly considered as part of the best-interests-of-the-child test when a court is deciding decision-making responsibility, parenting time, or contact. That's a different legal question from which ground you use to prove the marriage broke down. A history of family violence is addressed through the safety-focused parenting and support process, not by whether you selected "cruelty" instead of "separation" on your divorce application. If family violence is part of your situation, raise it directly with a lawyer — it belongs in the parenting and safety conversation, not buried in the choice of divorce ground.

Comparing the Three Grounds

GroundWhat you must showTypical useContested risk
SeparationLiving separate and apart for the required periodThe vast majority of Ontario divorcesLow
AdulterySpecific conduct, generally with evidenceRareHigher
CrueltyConduct intolerable enough to prevent cohabitationRareHigher

Frequently asked questions

Does using the separation ground mean I'm giving up on holding my spouse accountable?

No. Property division, support, and parenting arrangements are separate legal issues from the ground for divorce — choosing the simpler path to the divorce itself doesn't trade away any of those.

If my spouse actually did commit adultery, should I still just use separation?

In most cases, yes. Since the ground you choose doesn't affect your entitlements elsewhere, there's usually little practical benefit to proving fault, and real cost and delay in trying to.

Can I switch from a fault-based ground to separation partway through?

It's possible, and often advisable if a fault-based claim turns out to be contested or hard to prove. A lawyer can advise on amending the basis for your application.

Do I need special proof just to rely on separation?

You'll generally need to show, through your sworn documents, that you and your spouse have been living separate and apart for the qualifying period — no fault-based evidence is required.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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