Jo In Sung is a South Korean actor managed by IOK Company. He is best known for his leading roles in the television series "What Happened in Bali", for which he won at both the Baeksang Arts Awards and SBS Drama Awards, "That Winter, The Wind Blows", and "It's Okay, That's Love", which won the Daesang (Grand Prize), the highest honor for television at the APAN Star Awards.
Jo made his entertainment debut in 1998 as a model for clothing brand Ziozia. In 2000, he made his acting debut by starring in the teen series "School 3" and in the second season of the sitcom "Nonstop". In 2001, his supporting role in the television drama "Piano" drew attention to him.
He enrolled as a Theater and Film major at Dongguk University but was expelled in 2007 due to poor attendance.
He enlisted on April 7, 2009, for his mandatory military service, and served 25 months in the Air Force and the Air Force military band. He was discharged on May 4, 2011.
In 2016, Jo was chosen as an ambassador of the National Tax Service, alongside Choi Ji Woo.