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 South Dakota, hearsay is addressed under the South Dakota Rules of Evidence, specifically Rule 801 which defines hearsay and Rule 802 which generally prohibits the admission of hearsay evidence in court proceedings. Hearsay is considered to be an out-of-court statement that is presented to prove the truth of the matter asserted in the statement, and it is not made by a witness while testifying at the current trial or hearing. However, there are numerous exceptions to this general rule where hearsay may be admissible. These exceptions are outlined in Rule 803 and Rule 804 of the South Dakota Rules of Evidence and include circumstances such as statements made under the belief of imminent death, records of regularly conducted activity, and statements against interest, among others. Additionally, certain statements are defined as non-hearsay, such as a witness's own prior statement or admissions by a party-opponent. The application of hearsay rules and exceptions can be complex and often requires the interpretation of courts based on the specifics of each case.