Sung Yu-ri (Korean: 성유리; born March 3, 1981) is a South Korean actress and singer. She made her entertainment debut in 1998 as a member of the now-defunct K-pop group Fin.K.L. Sung turned to acting in 2002, starring in television dramas such as Thousand Years of Love (2003), The Snow Queen (2006), Hong Gil-dong (2008), and Feast of the Gods (2010).

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, and Kwang Nam High School, and graduated from Kyung Hee University with a Post Modern Music major in 2005.

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 (which stood for "Fine Killing Liberty"), one of the first Korean idol groups. Fin.K.L quickly rose in popularity, releasing four albums (Blue Rain (1998), White (1999), Now (2001), Eternity (2002)), 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 (2003). 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 comedy First Love of a Royal Prince (2004), 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 dramedy Hong 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 (titled Rabbit and Lizard in Korean).