Heo Seong Tae, born in Busan, is a South Korean actor with over 60 film and television credits. He graduated from Pusan National University where he majored in Russian. He came into national prominence as Ha Il Soo in the 2016 period thriller film, The Age of Shadows. Heo Sung Tae has debuted as an actor late at age 34 when on a drunken whim he participated in SBS's talent show Miraculous Audition. Prior to acting, he sold televisions in the Russian market for LG Corporation. He later joined the planning and coordination department of a shipbuilding company.
He became internationally famous for his role in Squid Game. He landed his first lead role in Insider in 2022.