What do I have to prove to win a defamation lawsuit in Ontario?

To win a defamation claim in Ontario, you generally need to prove three things: that the statement was defamatory, meaning it would tend to lower your reputation in the eyes of a reasonable person; that it referred to you specifically, even if you were not named directly, as long as a reasonable person would understand it was about you; and that it was published, meaning communicated to at least one person other than you.

Notably, Ontario defamation law generally does not require you to prove the statement was false, or that you suffered actual financial loss, at least initially - once those three elements are shown, falsity and harm are presumed, and the burden shifts to the defendant to raise a defence, such as truth, that can defeat the claim. This is a significant difference from many other kinds of civil claims, where the plaintiff carries the full burden of proof throughout the case. Because the defendant's available defences do much of the heavy lifting in a defamation case, understanding what defence might realistically apply matters just as much as proving the initial elements described here.