John Whitridge Williams (January 26, 1866 - October 21, 1931) was an American obstetrician. He received his A.B. from the Johns Hopkins University in 1886 and his M.D. from the University of Maryland in 1888. He spent the next year at universities in Berlin and Vienna studying bacteriology and pathology, and in 1889 he returned to Baltimore to be a volunteer assistant to Howard A. Kelly at the Johns Hopkins Hospital. Williams returned to Europe to study obstetrics and in 1892 joined the staff of the Johns Hopkins Hospital. When the medical school opened in 1893 Williams became an associate in obstetrics. He became associate professor of obstetrics in 1896 and professor in 1899. Williams served as dean of the school of medicine from 1911 until 1923. His main contributions to scientific research were in the pathology of obstetrical and gynecological disorders. He wrote over one hundred scientific papers and the standard Textbook of Obstetrics. He revised it many times, and the book is still in print under the title Williams' Obstetrics. He died in 1931 at the age of