Doc Hayward (played by Warren Frost) is a coroner, who, due to his close relationship with her, refuses to perform the autopsy on Laura Palmer. His first name is not generally used, but because he is referred to as "Will" in one episode, it can be presumed to be "William"; he is normally referred to as just "Doc" most of the time.

He is the husband of wheelchair bound Eileen, and father of three daughters Donna (who has by far the biggest role of the family), Harriet and Gersten. The Doc is generally a balanced, fair man, but he is especially upset by Laura's murder, as he is a friend of the Palmer family, and his daughters knew her well.

Doc Hayward also has an altercation with the abrasive Albert Rosenfield, who calls his work "amateur", and wishes to do more work on Laura's corpse. Unlike most of the characters on Twin Peaks he appears to have no major nasty secrets, or eccentricities. However, towards the end of the second season, we learn he may have been cuckolded by Benjamin Horne, fathering Donna. This is never resolved, though, because of the series' cancellation.