Yook Sung-jae (육성재) is a South Korean singer and actor. He is a member of the boyband BtoB.
- Known For: Acting
- Birthday: 1995-05-02
- Place of Birth: Yongin, Gyeonggi, South Korea
- Also Known As: 육성재, Yook Sung Jae, Sung-Jae Yook, 성재, Sungjae, 비투비, BTOB, Sung Jae Yook, Sungjae Yook, Yook Sungjae, 陆星材, ソンジェ