f(x) (; Korean: ) is a five-member multi-national K-pop girl group formed by S.M. Entertainment in 2009. The group consists of Victoria, Amber, Luna, Sulli, and Krystal. They are renowned for their experimental fashion and their eclectic, electropop sound.[ f(x)'s \u2018Red Light' video surpasses 2m hits on first day] (July 4, 2014). Retrieved July 4, 2014. Each member has also participated in other forms of entertainment, such as acting and television hosting.

f(x) is one of the few K-pop groups to receive international recognition, as they were the first K-pop act to perform at SXSW and their widely acclaimed second album, Pink Tape, was the only K-pop album chosen by the American music channel Fuse to be among the "The 41 Best Albums" of 2013.