Warren, John, 1753–1815, American surgeon, b. Roxbury, Mass.; grad. Harvard, 1771; brother of Joseph Warren. A leading surgeon of his time in New England, he served in the Revolution and was a founder of the medical school at Harvard, where in 1782 he was appointed professor of anatomy and surgery. His son, John Collins Warren, 1778–1856, b. Boston, grad. Harvard (M.D., 1797), taught (1809–47) at Harvard, serving as dean (1816–19) of the medical school. He was a founder of the Massachusetts General Hospital, where he was the first in America to operate on a strangulated hernia and where in 1846 he invited W. T. G. Morton to demonstrate ether anesthesia.