Patently unreasonable: Meaning (information, definition, explanation, facts)

Patently unreasonable or the patent unreasonableness test is a legal test created by common law and used in Canada by the court in the judicial review of administrative decisions. It is the highest of three standards of review, being correctness, unreasonableness, and patent unreasonableness. Although the term "patent unreasonableness" lacks a precise definition in the common law, it is somewhere above unreasonableness, and consequently it is difficult to prove that a decision is patently unreasonable. A simple example of a patently unreasonable decision may be one that does not accord at all with the facts or law before it, or one that completely misstates a legal test.

In theory, according to the Supreme Court of Canada in Baker v. Canada (Minister of Citizenship & Immigration), this standard of review could also apply in a statutory appeal. In practice, this is highly unlikely, since a right of appeal often determines the standard of review to be lower.

Compare this to due process in U.S. law and Wednesbury unreasonableness in English law.