J. P. Nettl (1926–1968) was a historian best known for his two-volume biography of Rosa Luxemburg, which The New York Times described as a classic work that did full justice to her political activity, context, theoretical contributions, and personality. He lived in England from 1936. After serving with British army intelligence during the Second World War, he studied at Oxford. He died in a plane crash in the United States in 1968.