Judicial notice is a court’s acceptance of a well-known and indisputable fact without requiring the party relying on the fact to prove it. The doctrine of judicial notice is one of common sense, and is based on the theory that where a fact is well-known in the community—or its existence is easily determined from sources that cannot be reasonably questioned—it would not be a good use of judicial time and resources to require formal proof of the fact in court. A court may take judicial notice of both facts and laws.

In Oregon, the concept of judicial notice is governed by the Oregon Rules of Evidence, specifically Rule 201. This rule allows courts to recognize and accept certain facts that are commonly known within the territorial jurisdiction of the court or can be accurately and readily determined from sources whose accuracy cannot reasonably be questioned. Judicial notice can be taken at any stage of the proceeding, whether requested by a party or not, and applies to both adjudicative facts and law. Adjudicative facts are those that typically go to the questions of who did what, where, when, how, why, with what motive or intent; whereas law includes statutes, administrative rules, and ordinances. The court may take judicial notice of law without a request, but it must take notice if a party requests it and provides the necessary information. The Oregon appellate courts have also upheld the use of judicial notice for facts and laws that meet the criteria of being well-known or easily verifiable.