Hiram Winnett Orr (March 17, 1877 – October 11, 1956) was an American orthopedic surgeon who was born in Pennsylvania and was raised and lived the rest of his life in Nebraska.

Carrel had pioneered the treatment of wounds with the expectation that infection was inevitable without proper care, and had helped create an antiseptic called the Carrel-Dakin solution.

[1] While in France, Orr took the Carrel treatment further by cleaning wounds, packing them with petroleum soaked gauze (to prevent sticking), and then setting the fracture and immobilizing it with plaster-soaked bandages that would harden quickly.

Brilliant in its application, yet ingeniously simple, the cast method required little expense (bandages, plaster and water), minimal time for the physician, and provided a faster and more effective cure for broken bones.

[2] By the time of Orr's death, the cast had become such a routine part of childhood that a broken leg meant that one's friends would "autograph" the dried plaster while the patient endured a relatively minor inconvenience.