When does the two-year limitation period start to run in Ontario?

In Ontario, the two-year limitation period under the Limitations Act, 2002 does not automatically begin on the date of the alleged wrong. It starts on the date the claim was "discovered" — meaning the earliest date on which a person knew, or ought reasonably to have known, four things: that the injury, loss, or damage occurred; that it was caused by or contributed to by an act or omission; that the act or omission was that of the person you want to sue; and that a court proceeding would be an appropriate way to seek a remedy.

This discoverability principle protects claimants who had no realistic way of knowing they had a legal claim right away. For example, if you were harmed by a product defect that was not reasonably detectable for several months, your two-year clock likely starts when you discovered (or a reasonable person in your position would have discovered) the connection between the defect and your harm — not on the date of purchase.

Courts apply an objective standard: they ask when a reasonable person with your background and circumstances would have discovered the claim. Waiting to confirm you have a strong case, or delaying while hoping to resolve things informally, does not stop the clock. If in doubt about whether your claim is still within time, speak with a lawyer promptly — the cost of missing a limitation period is permanent loss of the right to sue.