The group received the title of "Asian Pop Dance Group" by their label and are touted as a multinational group since f(x) consists of members from China, United States and South Korea.
2009: Debut with "La Cha Ta"
f(x) officially debuted with the release of their digital single "La Cha Ta" on September 5, 2009.
2014-2015: Sulli's hiatus and departure
During promotions for Red Light in July 2014, Sulli took a break from all activities due to being mentally and physically exhausted from the continuous, malicious comments and false rumors that had been spread about her. SM Entertainment later announced to take legal action against the individual spreading malicious rumors. Two months later, SM announced the person behind the rumors was caught and filed a suit against them on charges of defamation. However, charges against the accused were dropped by SM and Sulli after the accused apologized.
On August 7, 2015, SM announced that Sulli had officially left f(x) to focus on her acting career.
2016–2021: Inactivity and departures from SM
The group largely went inactive since 2016 with no news of new releases as the members pursued individual activities.
On the day of the group's 10 year anniversary, September 5, SM Entertainment shared that both Luna and Victoria have chosen not to renew their contracts with SM. The latter's contract with them was still under discussion, while Krystal still has time remaining before her contract expires.
On October 10, 2020, it was announced that Krystal had officially left SM Entertainment and signed an exclusive contract with H& Entertainment. On April 9, 2021, SM Entertainment announced that Victoria's contact with the company had ended.
On April 23, 2021, during a review video of her activities from debut to present, Luna expressed confusion over f(x) being referred to in the past tense, stating that the group had not yet disbanded.
|Victoria (빅토리아)||Leader, Main Dancer, Lead Rapper, Vocalist, Visual||2009–2019|
|Amber (엠버)||Main Rapper, Vocalist||2009–2019|
|Luna (루나)||Main Vocalist, Lead Dancer||2009–2019|
|Krystal (크리스탈)||Lead Vocalist, Visual, Face of the Group, Maknae||2009–2019|
|Sulli (설리)||Lead Rapper, Vocalist, Visual||2009-2015|