Charles-Eugène Quinquaud (26 December 1841, Lafat – 9 January 1894, Paris) was a French internist and dermatologist.
He studied medicine in Limoges and Paris, receiving his doctorate in 1873.
While working as a hospital interne, he was influenced by Pierre-Antoine-Ernest Bazin to study dermatology.
In 1878 he became médecin des hôpitaux, obtained his agrégation in 1883, and from 1886 served as chef de service at the Hôpital Saint-Louis in Paris.
During his career, he worked closely with dermatologists Ernest Besnier, Jean Alfred Fournier and Émile Vidal.
In 1892 he was elected as a member of the Académie de Médecine.In 1888 he described folliculitis decalvans, a scalp disease sometimes referred to as "Quinquaud’s disease".
His name is also associated with "Quinquaud's sign", a form of finger tremor with a sideways finger movement from the interossei.
The phenomenon was first described in alcoholics, and its description was first published by a student of Quinquaud's, six years after his death.In 1882, with physiologist Nestor Gréhant, he developed a method for determining blood volume through the use of carbon monoxide.