Ontario Court of Appeal confirms employers must prove availability of comparable employment, not merely criticizing the Plaintiff’s job search efforts.

In the recently decided case of Williamson v. Brandt Tractor Inc., 2026 ONCA 272, the Ontario Court of Appeal reinforces a critical limit on the “failure to mitigate” defence in wrongful dismissal cases: employers must do more than criticize an employee’s job search and failure to mitigate their damages; they must prove that comparable employment actually existed.

In this case, the employer argued the employee failed to mitigate by not pursuing similar sales roles. The Court rejected that argument outright. It confirmed that an employer bears a two-part burden:

• the employee failed to take reasonable steps to seek comparable work; and
• comparable employment was available such that the employee could likely have secured it.

On the facts, neither party provided evidence of available comparable positions that existed during the claimed notice period. That gap was fatal to this argument by the employer. The employee’s decision not to pursue sales roles did not relieve the employer of its burden.

What this Means in Practice

The duty to mitigate remains a cornerstone of wrongful dismissal law. Employees must take reasonable steps to find new, comparable employment to mitigate their damages following dismissal. However, Williamson underscores that mitigation is not judged in a vacuum:

• Employees only need to pursue employment opportunities that are truly comparable.
• Employers must support their own lack of mitigation argument with evidence that comparable alternative employment existed (e.g., job postings, market data).
• The Court may not accept speculative claims about what “might have been available.”

Why it matters for Alberta Employers

Although this is an Ontario Court of Appeal decision and not binding in Alberta, it is likely to be persuasive. Going forward, Alberta courts may adopt this same evidence-driven approach and employers engaged in wrongful dismissal litigation should operate cautiously by collecting and producing evidence of alternative comparable employment in case this same approach is adopted in Alberta.

Written by Brody Sikstrom and Carmelle Hunka