English physician who pioneered in the treatment of endocrine disorders. He was one of the first to use extractions of animal thyroid to relieve myxedema (severe hypothyroidism) in humans.

Murray, the son of a prominent physician, William Murray, received clinical training at University College Hospital, London. He was awarded both his M.B. (1889) and M.D. (1896) by the University of Cambridge. Determined to pursue a career in experimental medicine, Murray in 1891 became pathologist to the Hospital for Sick Children in Newcastle. He also lectured in bacteriology and comparative anatomy at Durham University. From 1893 to 1908 he was Heath professor of comparative pathology at Durham. Appointed to the chair of medicine at Manchester University, he remained there to the end of his career.

In 1891 Murray published his most important research, a report in the British Medical Journal on the effectiveness of sheep thyroid extract in treating myxedema in humans. Thyroid deficiency had been recognized as the cause of myxedema in the 1880s, and several researchers had established that an animal could survive the usually fatal effects of thyroidectomy if part of the excised thyroid gland was transplanted to another body location. Sir Victor Horsley, a colleague of Murray's, later suggested that part of a sheep's thyroid could be transplanted into human patients to relieve myxedema. Murray surmised, however, that a hypodermic injection of thyroid extract could more effectively be used to correct myxedema in humans, and he was completely successful in his first such attempt at treatment. Subsequent tests substantiated his approach.