What counts as irreparable harm when seeking an injunction in Ontario?

Irreparable harm means harm that money damages couldn't adequately fix later if you had to wait until trial to get a remedy - not simply harm that's serious or upsetting, but harm that's genuinely difficult or impossible to compensate with a cash award after the fact. Classic examples include loss of a unique piece of property (since one specific parcel of land or a one-of-a-kind asset can't be replaced with money the way a fungible loss can), permanent damage to reputation or goodwill that's hard to quantify or reverse, disclosure of confidential information that can't be "undisclosed" once it's out, or a business that would be destroyed or permanently disrupted before the case could ever reach trial.

Ordinary financial loss, even a large one, generally does not qualify as irreparable harm on its own if the defendant is capable of paying a judgment later - courts reason that if money can fix it, damages at trial are the proper remedy, not an injunction beforehand. Because irreparable harm has to be demonstrated with real evidence, not just asserted, showing why your specific situation can't simply be resolved with money later is usually the most important part of this stage of an injunction application.