What standard of proof applies in a civil lawsuit in Ontario?

In Ontario civil cases — including Small Claims Court — the standard of proof is the balance of probabilities. This means you must show that it is more likely than not (i.e., more than 50%) that your version of events is true. It is often described as showing something is "more probable than not."

This is a lower standard than the criminal standard of "beyond a reasonable doubt," which is why someone can be found not guilty in criminal court but still be held civilly liable for the same conduct. A civil defendant can be ordered to pay damages based on a finding that is "more likely than not" true, even if there was reasonable doubt about the same facts in a criminal proceeding.

In practice, this means you do not need perfect evidence or certainty. A credible account backed by documentary evidence, witness testimony, or reasonable inference from the circumstances can satisfy the civil standard. However, courts assess credibility carefully — inconsistent testimony, implausible explanations, and gaps in evidence can all weigh against you even under the lower civil standard.

Some allegations in civil cases — such as fraud — require "clear and convincing" evidence proportionate to the seriousness of the allegation, though the formal standard remains balance of probabilities.