Limitation Periods for Minors and Incapable Persons in Ontario

Ontario's limitation periods are designed to ensure that legal claims are brought forward while evidence is still fresh. But those rules can produce unfair results when the injured party is a child or someone who lacks the mental capacity to manage their own legal affairs. The law responds with a set of protective rules that modify how limitation periods work for these vulnerable groups.

If your child was injured, or if you are dealing with the aftermath of a claim involving someone who lacks legal capacity, understanding these rules can be the difference between a live claim and a permanently lost one.

The General Rule for Minors

Under Ontario's Limitations Act, 2002, the two-year basic limitation period does not run against a minor — a person under 18 years of age — unless that minor has a litigation guardian or other representative who has the authority and capacity to start a legal proceeding on their behalf.

As of writing, this means: if a child suffers harm and has no litigation guardian, the two-year clock does not start until one of the following occurs:

• The child reaches the age of 18 (the age of majority in Ontario for most legal purposes), or
• A litigation guardian is appointed to act for the child

Once the child turns 18 or a litigation guardian is in place, the two-year limitation period begins to run (subject to the discoverability rule).

Always confirm the current rule with a lawyer, as the law can change and individual circumstances vary.

What Is a Litigation Guardian?

A litigation guardian is a person appointed to manage legal proceedings on behalf of someone who lacks legal capacity to do so themselves. For a minor, the litigation guardian is typically a parent or legal guardian. For an incapable adult, it may be a court-appointed guardian of property, an attorney under a power of attorney, or another person approved by the court.

The appointment of a litigation guardian is significant: it triggers the start of the limitation period. If your child has a parent or legal guardian who is already in a position to bring a claim on the child's behalf, the clock may start running earlier than you think — from the moment the litigation guardian had or ought to have had knowledge of the claim, not necessarily from the child's 18th birthday.

This is a critical and often misunderstood point. Parents and guardians who delay pursuing a child's claim — perhaps assuming there is unlimited time until the child turns 18 — may find that the limitation period started running earlier because of their own status as the child's representative.

The Incapable Adult

The same protective framework extends to adults who are incapable of commencing a proceeding. Ontario's Limitations Act, 2002 suspends the limitation period during any period in which a person is incapable of managing their own legal affairs due to a physical, mental, or psychological condition — provided they do not already have a litigation guardian or other representative with legal authority to act.

What constitutes incapacity for these purposes is a legal and medical determination, not a general sense of being "unwell" or "overwhelmed." The threshold is specific: the person must be unable to manage the proceeding, not merely disadvantaged or stressed.

When capacity is restored — or when a guardian is appointed — the two-year clock begins (or resumes) running.

The Ultimate 15-Year Limitation Period Still Applies

Even with these protective suspensions, Ontario's ultimate 15-year limitation period creates a hard backstop. As of writing, claims generally cannot be brought more than 15 years after the act or omission that caused the harm, regardless of the plaintiff's age or capacity — subject to certain exceptions.

This means that the protection for minors and incapable persons is meaningful but not unlimited. If the harm occurred when a child was very young, and 15 years have passed since the harmful act, the ultimate period may have expired even though the basic two-year period was suspended.

Certain claims — notably sexual misconduct — are exempt from limitation periods under the Act as of writing. Verify the current rules with a lawyer.

Practical Example: Child Injured at Age 5

A child is injured in a car accident at age 5. Her parents are her natural litigation guardians. Because her parents have authority to act on her behalf, the two-year clock may begin running from the point at which her parents discovered (or ought to have discovered) that she had a claim — not from her 18th birthday.

If her parents waited until she was 10 to consult a lawyer, they may find the limitation period already expired — even though she is still a minor. This is the trap that the litigation guardian rule creates.

What Parents and Caregivers Should Do

If your child is injured or harmed in a way that may give rise to a legal claim:

1. Consult a lawyer promptly — do not assume that minority gives you unlimited time
2. Document everything — accident reports, medical records, photographs, witness names
3. Track the date you first had reason to believe the harm was caused by someone else — that is the potential starting point of your limitation period as litigation guardian
4. Ask about interim steps — in some cases, a lawyer can issue protective proceedings on behalf of a minor while the full case is being assessed

When a Child Turns 18 Without a Guardian Having Acted

If no litigation guardian was appointed, or if no one brought a claim on the child's behalf, the two-year period begins to run when the child turns 18 — provided the claim has not already been time-barred by the ultimate 15-year period or by the guardian's own discovery date.

An 18-year-old who suffered harm as a child and whose parents never took legal action should consult a lawyer immediately upon reaching adulthood to understand whether a claim is still available.

Frequently asked questions