Last Updated: August 22 2026
How do Ontario negligence courts decide whether the harm was reasonably foreseeable?
In Ontario negligence claims, courts apply an objective “reasonable foreseeability” test: the question is whether someone in the defendant’s position ought reasonably to have foreseen that the specific conduct could cause harm to someone, without using hindsight after the event. The Supreme Court explains that foreseeability looks to risk of harm that should have been anticipated before the incident, not whether it actually happened, and it also ties into remoteness and fairness in holding a defendant liable. In practice, this means you assess the “real risk” a reasonable person would not brush aside as far-fetched, including whether harm was too unrelated to the wrongful conduct, and courts may consider what a person of ordinary fortitude would likely suffer for injury types like mental injury. If you need help applying these principles to your facts, paralegal guidance from Caruso Legal Services can help you organize your evidence and assess claim strength in Ontario; call (289) 271-0488 to discuss your situation today.
Add this website to Google Preferred Sources
Understanding Foreseeability Principles
The principle of reasonable foreseeability applies within negligence law. To simplify, reasonable foreseeability involves the awareness of risk of harm that might arise from a specific behavior. As the basics of negligence law involve the question of what a reasonably minded person would do in a given situation, it is necessary to review what a reasonably minded person might foresee as a potential risk arising from the specific behaviour that is being challenged as unreasonable.
Note: Please contact Caruso Legal Services by phone at: (289) 271-0488 to discuss any specific questions that you may have.
The Law
The Supreme Court explained reasonable foreseeability and remoteness principles in Rankin (Rankin’s Garage & Sales) v. J.J., [2018] 1 S.C.R. 587, and Mustapha v. Culligan of Canada Ltd., [2008] 2 S.C.R. 114, by stating:
[53] Whether or not something is “reasonably foreseeable” is an objective test. The analysis is focussed on whether someone in the defendant’s position ought reasonably to have foreseen the harm rather than whether the specific defendant did. Courts should be vigilant in ensuring that the analysis is not clouded by the fact that the event in question actually did occur. The question is properly focussed on whether foreseeability was present prior to the incident occurring and not with the aid of 20/20 hindsight: L. N. Klar and C.S.G. Jefferies, Tort Law (6th ed. 2017), at p. 212.
[12] The remoteness inquiry asks whether “the harm [is] too unrelated to the wrongful conduct to hold the defendant fairly liable” (Linden and Feldthusen, at p. 360). Since The Wagon Mound (No. 1), the principle has been that “it is the foresight of the reasonable man which alone can determine responsibility” (Overseas Tankship (U.K.) Ltd. v. Morts Dock & Engineering Co., [1961] A.C. 388 (P.C.), at p. 424).
[13] Much has been written on how probable or likely a harm needs to be in order to be considered reasonably foreseeable. The parties raise the question of whether a reasonably foreseeable harm is one whose occurrence is probable or merely possible. In my view, these terms are misleading. Any harm which has actually occurred is “possible”; it is therefore clear that possibility alone does not provide a meaningful standard for the application of reasonable foreseeability. The degree of probability that would satisfy the reasonable foreseeability requirement was described in The Wagon Mound (No. 2) as a “real risk”, i.e. “one which would occur to the mind of a reasonable man in the position of the defendan[t] . . . and which he would not brush aside as far-fetched” (Overseas Tankship (U.K.) Ltd. v. Miller Steamship Co. Pty., [1967] A.C. 617 (P.C.), at p. 643).
[14] The remoteness inquiry depends not only upon the degree of probability required to meet the reasonable foreseeability requirement, but also upon whether or not the plaintiff is considered objectively or subjectively. One of the questions that arose in this case was whether, in judging whether the personal injury was foreseeable, one looks at a person of “ordinary fortitude” or at a particular plaintiff with his or her particular vulnerabilities. This question may be acute in claims for mental injury, since there is a wide variation in how particular people respond to particular stressors. The law has consistently held — albeit within the duty of care analysis — that the question is what a person of ordinary fortitude would suffer: see White v. Chief Constable of South Yorkshire Police, [1998] 3 W.L.R. 1509 (H.L.); Devji v. Burnaby (District) (1999), 180 D.L.R. (4th) 205, 1999 BCCA 599; Vanek. As stated in White, at p. 1512: “The law expects reasonable fortitude and robustness of its citizens and will not impose liability for the exceptional frailty of certain individuals.”
As per Rankin and Mustapha, foreseeability involves the question of whether a person could rationally anticipate that certain actions might bring about harm to another person. Furthermore, in line with the Rankin and Mustapha case decisions, when analyzing whether harm was foreseeable, a court is required to consider the event from the perspective of foresight as opposed to looking back with hindsight after harm has actually occurred.
Conclusion
Negligence law involves the scrutiny of whether an individual acted without proper care and should be held accountable for the harm caused to another person. A component of the scrutiny into whether actions were without proper care involves the inquiry into whether the harm caused could be rationally seen as a possibility. If the harm was rationally unforeseeable, then negligence failed to occur.
NOTE: A significant number of online searches featuring “lawyers near me” or “best lawyer in” frequently indicate a desire for prompt and competent legal assistance rather than a particular professional designation. In Ontario, licensed paralegals are governed by the same Law Society that regulates lawyers and are permitted to represent clients in specified litigation matters. Key components of this role include advocacy, legal analysis, and procedural expertise. Caruso Legal Services provides legal representation within its licensed parameters, focusing on strategic positioning, evidentiary preparation, and compelling advocacy aimed at achieving effective and positive outcomes for clients.
