Alphonse François Marie Guérin (in French pronounced as /alfɔ̃s fʁɑ̃swa maʁi ɡeʁɛ̃/; August 9, 1816 – February 21, 1895) was a French surgeon who was a native of Ploërmel.
He studied medicine in Paris, and in 1850 became a surgeon of Parisian hospitals. During his career, he practiced surgery at the Lourcine, Cochin, Hôpital Saint-Louis and Hôtel-Dieu. In 1868 he became a member of the French Académie Nationale de Médecine.
In 1870, Guérin introduced the practice of using cotton-wool bandages for prevention of wound infections. He described a horizontal fracture of the maxilla immediately above the teeth and palate, that is known today as a "Le Fort I fracture", or sometimes as a "Guérin fracture".
He was a specialist in urologic surgery, and has a handful of genitourinary terms that contain his name: