F.T. Island (Korean: 에프티 아일랜드, Japanese: エフティー・アイランド; stylized as FTISLAND), short for Five Treasure Island, is a five-member South Korean pop-rock band. The members are Choi Jong-hoon (guitar and keyboard), Lee Hongki (lead vocals) Lee Jae jin (bass and vocals), Song Seung-hyun (guitar and vocals; replacing Oh Won-bin in 2009), and Choi Min-hwan (drums).

Their debut album, titled "Cheerful Sensibility", was the sixth best-selling album in 2007. Their debut song "Lovesick" topped the K-Pop charts for eight consecutive weeks.