Seo In Guk is a South Korean singer and actor. He launched his singing career after winning the talent reality show Superstar K in 2009, and made his acting breakthrough in tvN’s Reply 1997. Since then, he has starred in television series High School King of Savvy (2014), 38 Revenue Collection Unit (2016) and Shopaholic Louis (2016).

Seo In Guk was born on October 23, 1987, in Ulsan. He decided to become a singer at the age of ten, after being inspired by the Korean rock musician Kim Jung-min. He performed at family gatherings and school events, and went on to study Applied Music at Daebul University, also auditioning in entertainment agencies. After repeatedly being rejected and told to lose weight, he struggled with bulimia for a time.