Eun Ji-won (born June 8, 1978) is a South Korean rapper, singer, host, dancer, composer and leader of the first generation idol group Sechs Kies (젝스키스). After the group's disbandment in 2000, Eun pursued a solo career in 2001 with his first single ("A-Ha") and has mainly focused on hip hop since. In addition to his music career, he has appeared on hit shows like 2 Days & 1 Night, Reply 1997, New Journey to the West and Kang's Kitchen.
On April 14, 2016, Sechs Kies held a reunion concert for fans 16 years after their disbandment through the popular program Infinite Challenge. They have since returned to promote as a group and have signed a contract with YG Entertainment.