Litigation Guardians in Ontario: Representing Someone Who Lacks Capacity in a Lawsuit

Lawsuits assume every party can understand what's happening and give instructions to a lawyer. When someone involved in a case cannot do that — because of age, illness, injury, or a cognitive condition — Ontario's courts do not simply proceed without them. Instead, they require a litigation guardian: someone who steps in to make decisions about the case on that person's behalf.

This comes up often in estate-related disputes, where the party whose capacity is in question might be an elderly beneficiary, a person already under guardianship, or someone whose competence is central to the dispute itself. Understanding what a litigation guardian actually does — and does not do — helps everyone involved know what to expect.

What Is a Litigation Guardian?

A litigation guardian is a person appointed to conduct a lawsuit, or defend one, on behalf of someone who is a minor or who lacks the capacity to instruct a lawyer and manage their own participation in a case. Ontario's Rules of Civil Procedure require this whenever a party falls into one of those categories, whether that party is bringing the claim or defending against one.

The litigation guardian effectively stands in the party's shoes for the purposes of the lawsuit. The claim, and anything recovered through it, still belongs to the person being represented — not to the litigation guardian personally.

When Does a Court Require One?

A litigation guardian is typically needed when:

• The party is a minor.
• The party has already been found incapable of managing property or personal care, for example through a guardianship application.
• The party appears to lack the capacity to instruct a lawyer, even without a formal prior finding, and the court or the other parties raise the issue.

Capacity to instruct a lawyer in active litigation is a narrower, specific question — separate from the broader legal tests for managing property or personal care generally. Someone can struggle with the demands of a lawsuit without necessarily meeting a wider incapacity test in another context, so this is often assessed on its own terms.

Who Can Serve as a Litigation Guardian?

• A family member or close friend who is willing to act and has no interest in the litigation that conflicts with the represented person's interests
• An attorney already acting under a valid power of attorney, in some circumstances
• A guardian of property or of the person, where one has already been appointed
• The Public Guardian and Trustee, where no suitable family member or friend is available or willing to act

A litigation guardian does not need to be a lawyer — they still hire and instruct one — but the court does need to be satisfied that whoever takes on the role can fairly represent the party's interests for the life of the case.

What a Litigation Guardian Can — and Can't — Do

Generally can

• Give instructions to the lawyer conducting the case
• Weigh in on settlement discussions, subject to court approval of any final settlement
• Make decisions about procedural steps, such as what evidence to pursue

Generally cannot

• Settle the claim without the court reviewing and approving the terms
• Act if their own interests conflict with those of the person they represent
• Be paid out of any recovery simply for having taken on the role

Litigation Guardians in Will and Estate Disputes

Estate litigation is one of the places this issue comes up repeatedly, because so much of it already revolves around capacity. A will challenge might turn on whether the person who made the will had the capacity to do so; a passing of accounts or a dependant's support claim might involve a beneficiary who has since become incapable and needs someone to protect their interest in the outcome; a guardianship dispute might itself be the lawsuit.

Because the same family is often already dealing with a capacity question outside the courtroom, identifying early whether a litigation guardian is needed — and who is appropriate for the role — matters. Missing this step can put an entire case at risk of delay, or worse, procedural challenge later.

Frequently asked questions