Yoo Dong-geun (born June 18, 1956) is a South Korean actor. He is best known for his leading roles in the historical television dramas Tears of the Dragon, Empress Myseongseong, and Yeon Gaesomun. He was also an adjunct professor of 연기학담당 at Daekyeung University in 1997. Since 2007, Yoo has been an activist of Sunfull Movement, a non-profit organization against cyberbullying.