Jean Alfred Fournier (12 March 1832 – 23 December 1914) was a French dermatologist who specialized in the study of venereal diseases.
As a young man he served as an interne at the Hôpital du Midi as an understudy to Philippe Ricord (1800–1889). In 1863 he became médecine des hôpitaux, and from 1867 worked with Augustin Grisolle (1811–1869) at the Hôtel-Dieu de Paris. In 1876 he was appointed chef de service at the Hôpital Saint-Louis, and in 1880 became a member of the Académie de Médecine.
His main contribution to medical science was the study of congenital syphilis, of which he provided a description of in 1883. In his numerous publications he stressed the importance of syphilis being the cause of degenerative diseases. In addition he founded an organization called the Société Française de Prophylaxie Sanitaire et Morale.
His name is associated with the following three medical terms:
Along with his study of venereal disease, Fournier was also a medical historian, republishing works by erstwhile physicians that included Girolamo Fracastoro (1478–1553), Giovanni de Vigo (1460–1525) and Jacques de Béthencourt.