Clelia Duel Mosher, the daughter of Cornelius Duel Mosher, M.D. and Sarah Burritt Mosher, was born on December 16, 1863 in Albany, New York. She graduated from Wellesley College in 1891, and spent the next year studying at both Cornell University and the University of Wisconsin. She then attended Stanford University, receiving an A.B. in zoology in 1893 and a masters in physiology in 1894. She received her M.D. from Johns Hopkins University in 1900.

Dr. Mosher returned to Palo Alto to set up practice as a physician. She joined the Stanford faculty as a professor of personal hygiene in 1910, retiring as Professor emeritus in 1929. Interested particularly in women's health, she carried out her research and writing interests both as a physician and faculty member in the Department of Physical Hygiene, the linear ancestor of Stanford's Department of Athletics, Physical Education and Recreation.

Mosher was a fellow in the American Medical Association (1906-1936) and in the American Association for Advancement of Science. She was also a member of Phi Beta Kappa, Sigma Xi, and Kappa Alpha Theta. An avid genealogist, she was a member of the Daughters of the American Revolution.

Between 1901 and 1929, Mosher published twenty-one books, including four "War Sketches" which appeared in the Medical Woman's Journal, 1921. She died in Palo Alto in 1940.