Ryu Shi-won (born October 6, 1972) is a South Korean actor and singer. After he made his debut in the KBS drama Feeling (느낌) in 1994, Ryu pursued a singing career.
On December 12, 2004, Ryu went with a Taiwanese actress to Singapore for the presentation of the Star awards to Singaporean actors in the Mediacorp Star Awards 2004. The event was broadcast on Mediacorp's TV Channel 8.
Ryu revealed that he is the 14th-generation descendant of the Joseon Dynasty Prime Minister, Yu Seong-ryong.
Ryu Si Won was nicknamed "Ryucifer" (Ryu+Lucifer) because he killed a person back in 1995 after accidentally running down a pedestrian while he was driving his Le Mans late at night. He was investigated but did not get charged against any crimes as he made a settlement with the victim's family, but the tag of a murderer still follows him. Ryu is an amateur car racer and still enjoys his hobby to this date, which only fuels people's accusations against him.
After one of the dramas he appeared in-"Beautiful Days"- was aired in Japan, he has become very popular there. He's been very active both as an actor and a singer in Japan lately.
Ryu has studied photography for three years and has produced his own promo photos. Because of this, in 2009, he worked for the very first time with his co-actor Ko Soo and he is the man behind Ko's very first photo diary, "24 Hours with Ko Soo". It spans approximately 100 shots, which will be produced as a DVD. He also gives support to Ko for his career.