TO1 (formerly known as TOO) is a nine-member South Korean boy group under WAKEONE. They were formed through the 2019 survival show, Mnet’s World Klass where the members were chosen from a pool of 20 trainees.

The group debuted on April 1, 2020 as TOO, with the EP Reason For Being: 仁 supported by the title track “Magnolia”. On January 13, 2021, the group’s former agencies n.CH Entertainment and CJ ENM were involved in management disputes, which left the group to be transferred to WAKEONE, where they rebranded themselves as TO1 on March 28 of the same year and later released the mini album RE:BORN on May 20.

Originally consisting of 10 members, member Chihoon left the group on April 30, 2022, and members Minsu, Jerome, and Woonggi left the group on June 17, 2022, simultaneously members Daigo, Renta, and Yeojeong were added to the group.

Where their former name TOO stood as an acronym for the “Ten Oriented Orchestra”, TO1 stands for “TOgether as 1.” Each member of the group represents a value (Justice, Love, Trust, Courtesy, Number, Heart, Benevolence, Virtue, Life, Wisdom) and an element (Metal, Wood, Earth, Fire, Water).