Nathan Smith Davis Sr., A.M., M.D., LLD (1817-1904) was a physician who was instrumental in the establishment of the American Medical Association, and was twice elected its president. He became the first editor of the Journal of the American Medical Association.

Davis wrote the majority report of the committee of the AMA which, in 1870, barred blacks and women from membership in that association.
Davis's son and grandson of the same name themselves became physicians.