Warren was born in Boston to Dr. John Warren, a founder of Harvard Medical School. In 1802, Warren entered into partnership with his father and assisted his father during his lectures.

Along with his close friend James Jackson, Warren was instrumental in the founding of MGH and in Harvard Medical School’s move from Cambridge to Boston. Warren was appointed the hospital’s first surgeon, and he held an appointment on the staff until 1853. Along with Jackson, he also founded the New-England Journal of Medicine and Surgery in 1812.

Warren is best remembered for his role in the first successful demonstration of the use of ether for surgical anesthesia on October 16, 1846. As he finished operating on the patient, he turned to the audience and exclaimed: “Gentlemen, this is no humbug.” Some of the many organizations Warren was deeply involved with include the Massachusetts Temperance Society, Massachusetts Agricultural Society and Boston Society of Natural History.