John H. Girdner (March 8, 1856October 27, 1933) was a prominent New York surgeon and an associate of the noted surgeon Frank Hamilton, with whom he attended President James Garfield after Garfield was shot in 1881. Girdner was the inventor of a "telephonic bullet probe" that came into use before the first x-rays, and was a pioneer in skin grafting. He taught at medical schools and was the author of numerous satirical and philosophical articles for magazines.