HALO (; abbreviation for Hexagon of Absolute Light and Organization) was a South Korean boy band formed by Histar Entertainment in Seoul, South Korea. The group consisted of six members: Dino, Inhaeng, Ooon, Jaeyong, Heecheon and Yoondong. They debuted on June 26, 2014, with the single "Fever". The group later disbanded on May 8, 2019.
On May 8, 2019, HALO's contract with Histar Entertainment ended. Following the news, Heecheon, Youndoung, and Ooon (under his real name, Jeong Young-hoon) became participants in the reality competition series Produce 101 Japan. However, all members left the show prior to its finale, citing personal reasons.