Irish physician and a leader of the Irish, or Dublin, school of diagnosis, which emphasized the clinical observation of patients and which significantly advanced the fields of physical diagnosis and internal medicine.

Graves received his degree from the University of Dublin in 1818. After studying in London and on the European continent, he returned to Dublin in 1821 and set up the Park Street School of Medicine. He also served as a physician at Meath Hospital, introducing reforms in medical training that he had witnessed on his travels. In addition to teaching traditional textbook medicine, Graves assigned to advanced students the responsibility for diagnosis and treatment of ward patients, under the supervision of the faculty. Like other progressive professors of his times, he gave his lectures in English rather than in Latin. Graves was named regius professor of the Institute of Medicine in Trinity College in recognition of his achievements in education. A founder of the Dublin Journal of Medical Science, he served as one of the journal's editors until his death.

Graves was one of the first physicians to fully describe exophthalmic goitre, now called Graves' disease. His Clinical Lectures on the Practice of Medicine, published in 1848, are responsible for establishing his enduring reputation. Among the innovations introduced in the lectures were the timing of the pulse by watch and the practice of giving food and liquids to patients with fevers instead of withholding nourishment from them. Graves facetiously suggested that his epitaph should read, “He fed fevers.”