Who must be given notice when someone applies for guardianship of an incapable relative in Ontario?

An Ontario guardianship application generally requires notice to be given to the person alleged to be incapable themselves, since the application directly affects their legal rights, along with notice to their closest family members — typically a spouse or partner, adult children, parents, and siblings, depending on who is available — so that anyone with a genuine interest in the outcome has an opportunity to respond, support the application, or raise an objection.

The specific list of who must receive notice can vary depending on the incapable person's actual family circumstances and who is reasonably available and appropriate to be included, and the court expects the applicant to make real efforts to identify and notify the relevant people rather than limiting notice to those who are simply convenient or supportive of the application. Skipping proper notice to someone who should have received it can create problems later, including a challenge to the validity of the resulting order. Because getting the notice requirements right is an essential part of a properly prepared application, work with a lawyer to confirm exactly who needs to be notified in your specific situation.