Lawrence Harvey Cohn (March 11, 1937 – January 9, 2016) was an American heart surgeon, researcher, and medical educator. He was best known for his heart valve repair and replacement surgeries. He was on the surgical staff at Harvard Medical School from 1971 until his death. He was also Professor of Surgery at Harvard Medical School from 1980 until his death. He was awarded the Chair in Cardiac Surgery at Harvard Medical School in 2000.