Sooyoung was born in Gwangju, Gyeonggi, South Korea on February 10, 1990. She was discovered on SM Casting System via the 2000 SM Open Audition. She then auditioned for the 2002 Korea-Japan Ultra Idol Duo Audition and won first place, marking her debut into the Japanese music scene with the band Route 0.
Sooyoung graduated from Jungshin Women High School (Korean: 정신 여자 고등학교) in 2009 and is currently majoring in performing arts and theater at Chung-Ang University.
After winning first place in the 2002 Korea-Japan Ultra Idol Duo, Sooyoung was sent to Japan and debuted as a member of the duo Route 0, alongside Marina Takahashi. The band released three singles: "Waku! Waku! It's Love," "Start," and "Painting".
She also has appeared as lead actress in a number of Korean dramas, including The Third Hospital, Dating Agency: Cyrano, Squad 38, Polyclinic Doctor, and My Spring Days, of which she won "Excellent Actress" at both the 2014 MBC Drama Awards, and the 2015 Korean Drama Awards.