I.O.I: Loop

I.O.I: Loop (Korean: 아이오아이 : 루프; stylized in all caps) is the third extended play (EP) by South Korean girl group I.O.I. Produced by Swing Entertainment and distributed by Stone Music Entertainment and KT Genie Music, the EP was released on May 19, 2026. The EP marked the group's reunion to celebrate their tenth debut anniversary. Formed as a temporary project group from the television program Produce 101 (2016), I.O.I found success but only actively promoted for less than a year before disbanding in January 2017 as part of their contract. While the members pursued solo or group careers in their respective agencies, attempted reunions never materialized until it was announced in December 2025 that nine of the eleven members would reunite to release new music for their tenth anniversary. The EP features a total of six tracks, carried by its singles "Goodbye with a Smile" and "Suddenly". The physical version of I.O.I: Loop features one version, including a photo book, a CD, two random photo cards, a poster, a special printed photo, a mini accordion booklet and a photo taken with a Polaroid camera. I.O.I will promote the EP through their Loop Tour around Asia.