Silas Weir Mitchell was an American physician and writer.

During the Civil War he had charge of nervous injuries and maladies at Turners Lane Hospital, Philadelphia, and at the close of the war became a specialist in neurology. In this field Weir Mitchell's name became prominently associated with his introduction of the rest cure, subsequently taken up by the medical world, for nervous diseases, particularly hysteria; the treatment consisting primarily in isolation, confinement to bed, dieting and massage. His medical texts include Injuries of Nerves and Their Consequences (1872) and Fat and Blood (1877). Mitchell's disease (erythromelalgia) is named after him.