F-iV (Korean: 파이브; RR: pai-beu; also stylized as F-IV) is a four-member South Korean boy band composed of Seo Ji-won, Chang Hae-young, Woo Jung-tae, and Kim Hyun-soo. Formed in 1999, the group debuted in 2002 and became a popular boy band in the early 2000s in South Korea. During their career, the group released two albums and one EP.