Fromis 9 (Korean: 프로미스나인; styled in snake_case as fromis_9) are a South Korean girl group formed through the 2017 reality show "Idol School". The group currently consist of five members: Song Ha-young, Park Ji-won, Lee Chae-young, Lee Na-gyung, and Baek Ji-heon. They originally debuted as a nine-member group, with Jang Gyu-ri departing in July 2022, followed by Lee Sae-rom, Roh Ji-sun, and Lee Seo-yeon in February 2025.
The group debuted on January 24, 2018, with the extended play "To. Heart". At the time, they were managed by Stone Music Entertainment with production by Pledis Entertainment. Their management later transferred to Off the Record Entertainment in September 2018, before moving to Pledis Entertainment in 2021. Following the expiration of their contracts with Pledis Entertainment at the end of 2024, five members signed with Asnd in January 2025 and continued group activities, releasing their sixth extended play "From Our 20's" in June 2025.
The name "Fromis" was selected through suggestions by viewers of "Idol School" and chosen by CJ E&M. It is commonly interpreted as combining "From Idol School" and "Promise", reflecting the group’s stated aim to fulfil expectations. The suffix "9" was later added to represent the original number of members.
In March 2017, it was announced that the television channel Mnet would launch "Idol School", a survival programme designed to form a new girl group. The show aired from July to September 2017, with the final line-up determined by viewer voting. The nine selected members were Roh Ji-sun, Song Ha-young, Lee Sae-rom, Lee Chae-young, Lee Na-gyung, Park Ji-won, Lee Seo-yeon, Baek Ji-heon, and Jang Gyu-ri.
