Niels Christian Ditleff (29 October 1881 – 18 June 1956) was a Norwegian diplomat, noted for his humanitarian efforts on behalf of captives of the Germans during World War 2. In spite of opposition from his own and allied governments, he initiated and organized the White Buses campaign to rescue Scandinavian prisoners in German concentration camps. He was also instrumental in evacuating foreign diplomats from Warsaw during the German invasion and to rescue Jews in coordination with Nansenhjelpen.