Hearsay is a statement that (1) the person making it (the declarant) does not make while testifying at the current trial or hearing (in other words, the statement is made out of court); and (2) a party offers as evidence to prove the truth of the matter asserted in the statement.

Hearsay is generally not admissible as evidence—but there are many exceptions to hearsay, and statements that are non-hearsay. The law governing hearsay is usually located in the applicable state or federal rules of evidence, which are interpreted and applied by courts in court opinions or cases.

In Oklahoma, hearsay is typically inadmissible in court under the Oklahoma Evidence Code, which mirrors the Federal Rules of Evidence in many respects. Hearsay is defined as an out-of-court statement offered to prove the truth of the matter asserted and is not made by a witness while testifying at the current trial or hearing. However, there are numerous exceptions to this general rule. Some of these exceptions include, but are not limited to, statements made under the belief of impending death, statements against interest, certain statements of personal or family history, and records of regularly conducted activity. Additionally, there are statements that are not considered hearsay at all, such as a declarant-witness's prior statement if the declarant testifies at the current trial or hearing and is subject to cross-examination about the prior statement, and admissions by a party-opponent. The admissibility of hearsay in Oklahoma courts is ultimately determined by the judge, who will consider the rules of evidence, case law, and any relevant exceptions or exclusions that may apply to the statement in question.