Sung was born in 1981 in Tübingen, Baden-Württemberg, West Germany. Her father Sung Jong-hyun, a prominent professor of theology at the Presbyterian College and Theological Seminary, was studying at the time in West Germany. Sung's family returned to South Korea when she was four-years-old and she grew up in Gangdong District, Seoul. She attended Myung Elementary and Middle School, Kwang Nam High School and graduated from Kyung Hee University with Post Modern Music Major in 2005.
Career
When Sung was a high school student, she began her entertainment career in 1998 as the youngest member of the four-member K-pop girl group Fin.K.L, one of the very first Korean idol groups. Fin.K.L quickly rose in popularity, releasing four albums, White, Now, Eternity ), and various singles, live concert albums and compilation albums. But after the release of their fourth album, Sung and fellow band members Ock Joo-hyun, Lee Hyori and Lee Jin began doing solo activities. Sung made her acting debut in 2002 with Bad Girls, and a year later was cast in her first leading role in Thousand Years of Love. Sung learned horseback riding and martial arts in her role as a Baekje princess who time travels to modern-day South Korea. This was followed by the romantic comedyFirst Love of a Royal Prince, partly shot in Japan and Bali, in which Sung's fun-loving sandwich shop delivery girl was a departure from her previous feminine characters. During this time, she was harshly criticized for her acting. Sung graduated from Kyung Hee University in February 2005 with a degree in Theater and Film; she also received an Achievement Award for promoting her alma mater. After a brief return to music via Fin.K.L's digital single Corealism in late 2005, she decided to focus solely on her acting career. In line with this, all the Fin.K.L members left their agency DSP Entertainment, and Sung joined SidusHQ in June 2005. In 2006, she starred in One Fine Day and The Snow Queen, playing, respectively, an orphan adopted by a wealthy but suffocating family, and a cold-hearted heiress with an incurable disease. But it was fusion-period dramedyHong Gil-dong in 2008 that changed how the industry perceived Sung as an actress. The series' screenwriters, the Hong sisters were initially criticized for casting her, but they defended Sung, and her portrayal of a tomboyish, vanity-free outlaw drew a positive reception from audiences. Sung then played an aspiring show director who joins the Cirque du Soleil in Swallow the Sun, a 2009 big-budget action-romance series with overseas location shoots in Las Vegas and South Africa. That same year, she also appeared in her first big-screen starring role as a Korean-American adoptee who returns to her native country to search for her biological mother in Maybe. In 2011, Sung left SidusHQ and transferred to King Kong Entertainment. She then starred in Romance Town, in the role of a maid who wins in the lottery and keeps it a secret from her boss and fellow household help. A more traditional melodrama followed with Feast of the Gods, about two rival female chefs of Korean royal court cuisine. Afterwards, Sung reunited onscreen with previous Hong Gil-dong co-star Kang Ji-hwan in the action-comedy filmRunway Cop, which revolves around a detective who goes undercover as a fashion model for a drug case. In 2013, she played a genius with psychogenic amnesia in The Secret of Birth. The low-budget indieA Boy's Sister was then released, in which Sung played the titular character who's grieving after her brother's death. Later that year, she replaced Han Hye-jin as one of the hosts of talk show Healing Camp, Aren't You Happy. When Sung's contract with King Kong Entertainment expired in January 2014, she signed with Fantagio. She then appeared for free in the short film Chorogi and the Stalker Guy which screened at 6th Seoul International Extreme-Short Image & Film Festival. Sung next played a diva actress who unexpectedly falls for her loyal manager in the 2015 omnibusSummer Snow. On April 20, 2015, Sung signed an exclusive contract with SL Entertainment. She next starred in the revenge melodrama Monster.
Personal life
Sung married golfer Ahn Sung-hyun in May 2017 in a low-key private ceremony. They had been dating for four years and did not publicly announce their marriage until after the ceremony.
