Adolf Meyer (September 13, 1866 – March 17, 1950) was a psychiatrist who rose to prominence as the first psychiatrist-in-chief of the Johns Hopkins Hospital (1910-1941). He was president of the American Psychiatric Association in 1927-28 and was one of the most influential figures in psychiatry in the first half of the twentieth century. His focus on collecting detailed case histories on patients is the most prominent of his contributions.