Isabella Herb (née Coler; November 6, 1863/1864 – May 28, 1943) was an American medical pioneer in the fields of pathology and anesthesiology. Her career spanned more than half a century, ending with her retirement in 1941. She was the first woman physician to specialize in anesthesiology, and the first Mayo Clinic specialist in her areas of expertise. In 1933, Herb designed the Herb–Mueller apparatus for administering ether to patients. She was the head of the Department of Anesthesia at Presbyterian Hospital, and the first woman president of the American Association of Anesthetists.