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 New York, judicial notice is a principle that allows courts to accept certain facts that are commonly known or easily verifiable without requiring formal proof. This doctrine is codified in the New York Civil Practice Law and Rules (CPLR) under Article 45, which governs the admissibility of evidence. Specifically, CPLR Section 4511 allows courts to take judicial notice of the law of New York, federal law, and the law of any other jurisdiction in the United States. Additionally, under CPLR Section 4511-b, courts may take judicial notice of certain facts that are not subject to reasonable dispute because they are generally known within the territorial jurisdiction of the court or can be accurately and readily determined from sources whose accuracy cannot reasonably be questioned. This can include information such as historical events, data from government reports, and scientific facts. The use of judicial notice is intended to streamline legal proceedings by avoiding the need to prove facts that are already commonly accepted or easily verifiable.