Bang Yong-guk (Korean: 방용국; born March 31, 1990), also known mononymously as Yongguk (용국), is a South Korean rapper, singer, songwriter, and record producer, who served as the leader of boy group B.A.P up until his departure from TS Entertainment in August 2018.

He made his musical debut in 2008 as a member of an underground hip hop group called Soul Connection under the alias of "Jepp Blackman". In March 2011, he featured on Song Ji-eun's single "Going Crazy", which became a number one hit in South Korea. In July of that year he released his first solo digital single, "I Remember", featuring Beast's Yoseob and in November he promoted in a sub-unit called Bang & Zelo with fellow B.A.P member Zelo, releasing the single "Never Give Up". B.A.P released their first single in January 2012.