Adult guardianship in Ontario — your questions answered

Guardianship is a legal arrangement in which a court appoints a responsible person — called a guardian — to make decisions on behalf of an adult who is no longer able to make those decisions themselves. A court may appoint a guardian when a loved one has lost decision-making ability due to dementia, a serious brain injury, a stroke, mental illness, or another condition that affects their capacity.

Guardianship is typically considered a last resort. It is only necessary when there is no valid Power of Attorney already in place, or when existing arrangements are no longer working.

Under Ontario’s Substitute Decisions Act, 1992, every adult over 18 is presumed to be mentally capable unless there is evidence to the contrary. Mental capacity is not all-or-nothing — a person may be capable of making some decisions but not others.

The legal test focuses on whether the person is able to understand the information relevant to a decision and to appreciate the reasonably foreseeable consequences of making — or not making — that decision. Capacity is assessed by a trained health professional called a Capacity Assessor.

Yes. Ontario law recognises two distinct types of court-appointed guardianship:

• Guardian of Property — responsible for managing the person’s finances and assets.
• Guardian of the Person — responsible for personal care decisions such as housing, health care, nutrition, and safety.

It is possible to apply for one type without the other. We can help you determine which applies to your situation.

Any person who is at least 18 years of age and mentally capable can apply. Applicants are most often spouses, adult children, siblings, or close friends of the incapable person. A trust corporation may also be appointed in appropriate circumstances. The court will consider who is best placed to act in the incapable person’s best interests.

Guardianship applications are made to the Ontario Superior Court of Justice and involve several key steps:

• A capacity assessment confirming the person is mentally incapable.
• A sworn affidavit setting out the evidence of incapacity and the proposed guardian’s plan.
• A Management Plan (property) or Guardianship Plan (personal care) in the prescribed form.
• Service on the incapable person, any attorney under a power of attorney, their immediate family, and the Office of the Public Guardian and Trustee (OPGT).
• A court hearing at which a judge reviews the evidence and decides whether to grant the order.

Every case is different. The timeline depends on how quickly a capacity assessment can be arranged, the complexity of the person’s situation, and court scheduling. In straightforward, uncontested cases, the process can sometimes be completed in a few months. Where there are contested issues — for example, a family dispute about who should be guardian — it may take considerably longer.

We will give you a realistic assessment of the expected timeline once we have reviewed your specific circumstances.

The Office of the Public Guardian and Trustee (OPGT) is a provincial government office that protects the interests of mentally incapable adults. In every guardianship application, the OPGT must be served with the court documents and is entitled to participate in the proceedings. The OPGT may raise concerns, request additional information, or oppose the appointment if it does not believe the proposed guardianship is in the incapable person’s best interest.

The Government of Ontario publishes publicly accessible information about adult guardianship on its website. The main resource is the ontario.ca page on Guardianship, which provides an overview of guardianship of property and guardianship of the person, explains the difference between guardianship and a power of attorney, and describes the steps involved in applying to become a guardian. It also includes links to the prescribed Management Plan and Guardianship Plan forms.

The Office of the Public Guardian and Trustee (OPGT) also maintains a page with information about its role, contact details for each regional office, and instructions for serving court documents on the OPGT.

The Government of Ontario maintains a searchable list of capacity assessors on ontario.ca. The list is maintained by the Capacity Assessment Office and can be filtered by region, language, and area of specialty. The Capacity Assessment Office can also be reached directly at CAO@ontario.ca or toll-free at 1-800-366-0335 if you need help locating an assessor or have questions about fees or financial assistance.

We can also help — both in identifying an appropriate assessor for your situation and in working with them as part of the guardianship application process. Contact us if you would like guidance on this.

The total cost varies depending on the complexity of the matter, whether the application is contested, and the amount of legal work involved. There are generally two categories of cost:

• Legal fees — charged for time spent preparing your application, advising on your duties, drafting the required plan, and representing you before the court. We provide a fee estimate at your initial consultation. Flat rates are often available for straightforward, unopposed matters.
• Disbursements and third-party costs — including the Capacity Assessor’s fee, court filing fees, and process server fees for serving the application. The Capacity Assessor fees vary between Assessors, and typically make up the most significant component of the cost, after the lawyer’s legal fees.

In many cases, the reasonable legal costs of the application can be paid from the incapable person’s estate or assets, subject to the court’s approval.

We typically work on an hourly rate basis for guardianship matters and provide a written retainer agreement that clearly sets out our rates before we begin. For some straightforward aspects of the work, a flat-fee arrangement may be available. We encourage you to ask about fees openly at any stage — we want you to feel confident and informed about what you are investing in.

Legal Aid Ontario does not generally cover guardianship applications, as these are civil proceedings. However, there may be other options worth exploring depending on your circumstances, such as duty counsel resources at the courthouse or community legal clinics that offer summary advice. We are happy to discuss your situation and help you understand all available options.

Your matter will be handled by Richard Nishimura, the managing partner of MZS Lawyers and a founding member of the firm. Richard is a civil litigation lawyer with more than 15 years of experience appearing before the Ontario Superior Court of Justice, the Court of Appeal, the Divisional Court, and other tribunals.

Richard is dedicated to helping vulnerable adults and their families navigate the guardianship process with clarity and compassion. While his practice is based in Ottawa, he is able to represent clients across Ontario for unopposed guardianship applications.

A graduate of Dalhousie Law School, Richard brings a practical, client-focused approach to every matter — explaining your options in plain language and guiding you through each stage of the application without unnecessary complexity.

The most important first step is to get legal advice early. Acting promptly can help protect your loved one from financial harm or gaps in care. At MZS Lawyers, we will listen carefully to your situation, explain your options in plain language, and help you decide on the best path forward — whether that is a guardianship application, a less formal arrangement, or something else entirely.