Yook Sung-jae, often known simply as Sungjae, is a South Korean singer, songwriter, actor, and TV host. He was born on May 2, 1995, in Yongin, Gyeonggi Province, South Korea. Sungjae participated in Cube Entertainment's stage performances in 2010 and 2011 before debuting as a vocalist for the boy group BtoB in 2012. His early solo activities included co-hosting SBS MTV's music program The Show and acting in the drama Monstar in 2013. In 2014, Sungjae appeared in the television series Reply 1994 and joined the project unit group Big Byung. His breakthrough came in 2015 with a leading role in the teen drama Who Are You: School 2015, earning him several awards. He continued to build his acting career with roles in The Village: Achiara's Secret (2015) and Guardian: The Lonely and Great God (2016-2017). In 2019, Sungjae became the leader of BtoB and launched the music project 3x2=6, releasing several singles. He made his solo debut with the album Yook O'Clock in 2020. That year, he also starred in the drama Mystic Pop-up Bar. Sungjae enlisted for mandatory military service in May 2020, serving in the Ministry of National Defense military band until his discharge in November 2021. In 2024, Sungjae released the single album EXHIBITION : Look Closely, which peaked at number 9 on the Korean Top 100.
