Judicial notice is a rule in the law of evidence that allows a fact to be introduced into evidence if the truth of that fact is so notorious or well-known, or so authoritatively attested, that it cannot reasonably be doubted. This is done upon the request of the party seeking to rely on the fact at issue. Facts and materials admitted under judicial notice are accepted without being formally introduced by a witness or other rule of evidence, even if one party wishes to plead evidence to the contrary.

Judicial notice is frequently used for the simplest, most obvious common sense facts, such as which day of the week corresponded to a particular calendar date or the approximate time at sunset. However, it could even be used within one jurisdiction to notice a law of another jurisdiction—such as one which provides average baselines for motor vehicle stopping distances.