I.O.I

I.O.I is an 11-member project girl group under Swing Entertainment formed through Mnet's survival show Produce 101. The group was managed by YMC Entertainment and CJ E&M, and officially debuted on May 4, 2016 with the mini album Chrysalis and its title track Dream Girls. Their name stood for "Ideal of Idol", reflecting the show's premise of creating a "national girl group" chosen directly by viewers.

The final lineup consisted of Nayoung, Chungha, Sejeong, Chaeyeon, Kyulkyung, Sohye, Yeonjung, Yoojung, Mina, Doyeon, and Somi. Because the members came from different agencies, I.O.I was always planned as a temporary group. During their short run, they promoted both as a full group and as a sub-unit, releasing songs like Whatta Man, Very Very Very, and Downpour.

Despite being active for less than a year, I.O.I became one of the most influential project groups in K-pop. Their success helped prove the power of survival-show fandoms and paved the way for later Produce groups like Wanna One, IZ*ONE, and X1. After their disbandment in January 2017, many members continued in the industry as soloists, actors, or members of groups such as Weki Meki, gugudan, DIA, PRISTIN, Cosmic Girls, and JEON SOMI as a solo artist.

In 2026, I.O.I reunited for a special 10th anniversary project, marking their first major group comeback in nearly a decade. The reunion featured nine members, with Mina and Kyulkyung not participating, and included the EP I.O.I : Loop, a pre-release track, and anniversary concerts in Seoul before additional Asia tour stops. Although I.O.I began as a temporary group, their legacy has lasted far beyond their original contract, making them one of K-pop's defining examples of how a short-lived project group could leave a permanent mark.