Oswalt Kolle (2 October 1928, in Kiel – 24 September 2010, in Amsterdam) was a German sex educator, who became famous during the late 1960s and early 1970s for his numerous pioneering books and films on human sexuality. His work was translated into all major languages, while his films found an audience of 140 million worldwide. In his 1997 book Open to Both Sides he came out as bisexual. He was awarded the Magnus Hirschfeld Medal in 2000.