F.I.R. (traditional Chinese: 飛兒樂團; simplified Chinese: 飞儿乐团; pinyin: Fēiér Yuètuán) is a popular Taiwanese band. Renowned producer Ian Chen formed his own band and recruited the other two members to form F.I.R. They are well known throughout Asia with their hit "Lydia," which was the theme song for the Taiwanese TV drama "The Outsiders(鬥魚)." The drama was aired in Taiwan without revealing the singer of the theme song. The song attracted many fans, which led to F.I.R.'s big success when they finally debuted in 2004. Since their debut, they have often been compared with the disbanded Japanese rock group, Do As Infinity, because of the similar music styles and formation of band members.
The name F.I.R. comes from the initials of the names of the three members: Faye, Ian, and Real. It is also a backronym for "Fairyland in Reality", one of their albums.