Song Du-yul (Korean: 송두율, born 12 October 1944) is a German philosopher and sociologist of Korean descent. A professor at the University of Münster, Germany, he has been a political exile from his native South Korea for over 40 years. Educated in South Korea, he left that country for Germany in 1967 to pursue higher education. He visited North Korea a total of 18 times while living in Germany, but did not return to the South until 2003. During his visit to the South that year, he was arrested, charged, and convicted of spying for the North under the South's National Security Act in a controversial court case; in the end, he was given a suspended sentence, and returned to Germany in August 2004.