Shi-yuan "Barbie" Hsu (Chinese: 徐熙媛; pinyin: Xú Xīyuán; 6 October 1976 – 2 February 2025), also known by her stage name Big S (大S; Dà S), was a Taiwanese actress, singer, and television host. She debuted alongside her younger sister Dee Hsu (小S; Xiǎo S) in 1994 as part of the musical duo S.O.S (Sisters of Shiu), which was later rebranded as A.S.O.S (Adult Sisters of Shiu) and transitioned into television hosting. The sisters co-hosted variety shows such as Guess (1996–2000) and 100% Entertainment (1998–2005) before Barbie shifted her focus to acting. As an actor, Hsu rose to pan-Asian fame with her leading role in the television drama Meteor Garden (2001–2002), which is credited with ushering in the idol drama genre and the golden era of Taiwanese television. She went on to star in dramas such as Mars (2004), Corner with Love (2007), Summer's Desire (2010), as well as in the films Connected (2008) and Reign of Assassins (2010). After her first marriage in 2010, she largely stepped back from her career. Hsu ranked 33rd on the Forbes China Celebrity 100 in 2010, 16th in 2011, and 45th in 2012.