Margaret Gladys Smith (10 February 1896 – 1 May 1970)[1] was a pathologist who spent over forty years working at the Washington University School of Medicine.

Perhaps best known for her work with the St. Louis encephalitis virus, she has also been referred to as a founder of pediatric pathology[2] and the "mother of cytomegalovirus.

Her specialization was influenced by the 1918 influenza epidemic; she recalled seeing stacks of pine coffins outside the morgue at Johns Hopkins.

[2] In 1967, they published the classic textbook on the field, the thousand page Pathology of Infancy and Childhood.

[1] Margaret Gladys Smith died of a heart attack in her home in Webster Groves, Missouri on May 1, 1970.