CanadaWhat standard of review applies when a court reviews a labour arbitration decision?
In Canada, courts apply the reasonableness standard when reviewing labour arbitration decisions, unless the issue is a true question of jurisdiction or constitutional law — then correctness applies.
What the Law Says
Canadian administrative law establishes the framework for judicial review of decisions made by statutory tribunals, including labour arbitrators. While no single statute codifies the standard of review for all labour arbitration, the Supreme Court’s decision in Dunsmuir v. New Brunswick sets the governing common law rule.
The Supreme Court of Canada in Dunsmuir confirmed that there are only two standards of review on judicial review: correctness and reasonableness.
For most questions of fact, discretion, policy, or interpretation arising within a tribunal’s home statute — including collective agreement interpretation by labour arbitrators — the reasonableness standard applies.
Courts must defer to the arbitrator’s decision if it falls within a range of possible, acceptable outcomes which are defensible in respect of the facts and law.
What Courts Have Said
The Supreme Court of Canada fundamentally reshaped the standard of review analysis in Dunsmuir, eliminating the prior 'pragmatic and functional' test and establishing a simplified two-standard framework.
The Court held that reasonableness is the presumptive standard for reviewing decisions of administrative tribunals exercising their 'home statute' jurisdiction — including labour arbitrators interpreting collective agreements — unless the issue is a true question of jurisdiction, constitutional law, or general law of central importance to the legal system.
What to Do
Identify whether the issue concerns interpretation of the collective agreement or enabling legislation (reasonableness applies).
Determine if the question raises jurisdiction, constitutional law, or a legal issue of central importance (correctness may apply).
File an application for judicial review within the applicable provincial deadline — typically 30 days from the award date.
Prepare arguments focused on whether the arbitrator’s decision was reasonable — i.e., transparent, justified, and intelligible — not whether the court would have decided differently.
Sources
Not legal advice. This article is general information based on publicly available sources, written for educational purposes. Laws change and individual situations vary. Consult a licensed attorney in your jurisdiction before acting on anything you read here. Last reviewed: 2026-06-08.