Emil Pfeiffer (1 March 1846 – 13 July 1921) was a German physician and pediatrician.

Emil Pfeiffer
Born	(1846-03-01)1 March 1846 Wiesbaden, Nassau
Died	13 July 1921(1921-07-13) (aged 75) Wiesbaden, Hesse-Nassau
Nationality	German
Alma mater	Humboldt University of Berlin
Known for	Describing infectious mononucleosis
Scientific career
Fields	Medicine

He studied medicine at the universities of Bonn, Würzburg, and Berlin. It was at Berlin where he received his doctorate in 1869.

As a pediatrician he dealt with issues of infant nutrition, campaigned for the establishment of children's homes and crèches. He is known for describing infectious mononucleosis (also known as "mono," "glandular fever," and "kissing disease"), an Epstein–Barr virus-induced infectious disease of the lymphatic tissue that also bears his name—Pfeiffer's disease.^[1]