Can I sue my insurance broker for failing to get me the right coverage in Ontario?

Yes. An insurance broker's job is to understand your risk and either obtain coverage that reasonably meets your needs or clearly tell you what isn't covered, and a broker who fails at that can be liable in negligence - separately from any claim against the insurer itself. This comes up often after a loss reveals a coverage gap the client didn't know about: a policy that excluded a risk the client specifically asked about, or coverage that lapsed without adequate warning.

The standard is what a reasonably competent broker would have done given what you told them about your risks and needs, not a guarantee of covering every possible loss. If you never disclosed a risk, or declined broader coverage after being properly advised of the gap, that weakens a negligence claim significantly. You'll typically need your broker file - applications, emails, and any recorded conversations about coverage options - to show what was actually discussed and offered. Damages are generally measured as the amount you would have recovered had proper coverage been in place, not simply the size of your underlying loss.