Choi Si-won (born February 10, 1987), sometimes mononymously credited as Siwon, is a Korean pop singer and actor. He is a member of super boy band Super Junior and its subgroup, Super Junior-M. Siwon is best known for his role in the 2006 Hong Kong historical action film A Battle of Wits as young Prince Liang Shi. Siwon can speak Korean, basic Mandarin, and very little Cantonese (Shown in his Hong Kong interview). He is also one of the first four Korean artists to be on Chinese postage stamps. Siwon was born and raised in an affluent, strict Protestant family in Seoul, South Korea. He was scouted by a talent agent when he was 16, who recommended him to audition for the Starlight Casting System to become an entertainer. Siwon's parents disapproved him pursuing in an entertainment career, so he had to secretly audition. He successfully passed auditions, and after consideration, his parents allowed him to sign under the talent agency SM Entertainment. Siwon said that although his father allowed him to sign the contract, he would not give any help to his son. He later moved into dormitories with fellow trainees and he was trained in areas of singing, acting, and dancing. He made his first appearance in a music video of The Grace's Dana when he was still a solo singer in 2003. A year after, he made a brief appearance in the short drama, Precious Family. In 2005, Siwon made a brief appearance in the KBS drama Eighteen, Twenty-Nine as the young Kang Bong-man.
Not long after Siwon's first television appearance, SM Entertainment released an announcement that he would officially debut as one of the twelve members in a boy band. This band later became officially known as Super Junior 05, the first generation of the rotational music group Super Junior. A few months before the debut of Super Junior 05, Siwon made his first official media appearance with band mate Han Geng as a runway model in a fashion show by Bum Suk.Super Junior 05 officially debuted on November 6, 2005 on SBS's music program Popular Songs, performing their first single, "TWINS (Knock Out)". Their debut performance attracted over 500 fans and also garnered oversea viewers from both China and Japan. A full studio album was released a month later, which debuted at #3 on the monthly MIAK K-pop album charts.After Siwon's appearances in Eighteen, Twenty-Nine and Precious Family, he was casted in a larger role for the mini-series Spring Waltz, playing the supporting role Park Sang-woo, the teenage cousin of a diligent and working young woman. Not long after Siwon's musical debut, he was casted in a large supporting role in the Hong Kong epic film A Battle of Wits starring opposite Andy Lau. The cast promoted the movie throughout China with a short tour of four cities in November 2006. While the film received mixed reviews, Siwon garnered positive notices for his performance. He also received praises from co-star Lau, stating that Siwon is a wonderful actor and that he sets a good example for young Hong Kong idols.Half a year after the release of A Battle of Wits, Siwon starred in the high school mystery/comedy film Attack on the Pin-Up Boys with other Super Junior members. He played the lead role as a controlling and severe class president who was one of the popular possible subjects of being attacked by mysterious forces. Despite positive critical ratings, that film did not do well in the box-office, but all four versions of the film's DVD were all sold out and broke chart records. A few months later, Siwon was cast in mini-drama Legend of Hyang Dan as the lead role, Lee Mong-ryong.Siwon is scheduled in April 2011 to film Taiwanese drama Extravagant Challenge (traditional Chinese: 華麗的挑戰) with Ivy Chen and fellow band member Donghae as the three main characters. It is a live-action adaptation of Japanese shōjo manga Skip Beat! by Yoshiki Nakamura to be shot in Taiwan.