Mark William Lippert is an American diplomat who has worked as the vice president for international affairs at Boeing since 2017. He previously served as the United States Ambassador to South Korea from 2014 to 2017. Prior to his tour as an ambassador, Lippert had served as Chief of Staff for Secretary of Defense Chuck Hagel, Chief of Staff for the National Security Council, and Assistant Secretary of Defense for Asian and Pacific Security Affairs in the Department of Defense. On March 5, 2015, he was attacked by a man wielding a knife in South Korea.