Dr. Lewellys Franklin Barker was born on September 16, 1867, in Norwich, Ontario.

He was a Canadian physician and an authority on eugenics, heredity, and neurology. He received his degree of Bachelor of medicine in 1890 from the University of Toronto Medical School. After interning at Toronto General Hospital, he came to Johns Hopkins in 1892 to join the staff of William Osler’s clinic. He later held a fellowship and served a residency in pathology, and, in 1897, he was appointed Associate Professor of Anatomy. While at Johns Hopkins, Barker travelled abroad to further his studies. He studied in Germany in Karl Ludwig’s physiological laboratory and toured the South Pacific, Asia, and India to study diseases common to these areas. In 1900, he became a Professor of Anatomy at the University of Chicago. He was appointed to the 1901 Federal Commission on Plague in San Francisco. In 1905, Barker returned to Johns Hopkins and was appointed Director of Medicine and Physician-in-Chief at The Johns Hopkins Hospital, succeeding William Osler. He established laboratories at Johns Hopkins for the study of infectious diseases, physiology, and chemistry. Barker specialized in the study of neurology, endocrinology, and internal medicine. He was highly regarded as a remarkable diagnostician. Barker received several honorary degrees, including one from the University of Toronto.

In 1903, he married Lilian Haines Halsey (1873–1961). He died on July 13, 1943, in Baltimore, Maryland.