[4] Ong was encouraged by his mother to pick up a musical instrument and started playing the drums after his sister began learning the piano.

[5] While playing the drums at a band contest in 2008, Ong was scouted as a trainee by the now-defunct entertainment company Lion Media.

[7] Despite being an acting trainee, Ong was sent as a representative by his company to participate in Produce 101 (season 2) due to his well-rounded skills in singing and dancing.

[11] He went on to represent the group in several appearances on variety shows such as Happy Together, The Return of Superman, and Saturday Night Live Korea.

He appeared on Living Together in Empty Room with Kang Daniel and Kim Jae-hwan,[22] and also became a cast member of the reality show Law of the Jungle Sabah, with his fellow group mate Ha Sung-woon, which aired from July 27, 2018, to September 21, 2018.

[24] Upon conclusion of his activities with Wanna One, Ong embarked on his first solo fan-meeting tour, titled "Eternity", in March and April 2019.

[29] Ong made his acting debut in the later half of the year, starring as the male lead in JTBC's youth drama At Eighteen, alongside Kim Hyang-gi and Shin Seung-ho.

[37] Intended as a fan-song, Ong participated in both the lyric writing and composition of the single,[38] and performed it on the first time during the Seoul leg of his tour on January 11.

[44] Ong took part in the composition and lyric writing of all the songs on the album, drawing his inspiration from his emotions and stories from the past year.

[45] He also made several appearances on variety shows, including Omniscient Interfering View,[46] as well as Master in the House,[47] Radio Star,[48] and Running Man.

[49] He also featured on You Hee-yeol's Sketchbook, performing his new single and displaying his drumming skills on the show's live music format.

[51] Ong began starring as the male lead in the JTBC drama More Than Friends, alongside Shin Ye-eun and Kim Dong-jun, playing photographer Lee Soo.

[53] Furthermore, Ong will also be making his film debut in the upcoming musical-movie, Life is Beautiful, starring Ryu Seung-ryong and Yum Jung-ah.

[56] Ong appeared alongside dancer, Noze, in Lee Seung-hwan and Sunwoo Jung-a's music video for the song "How could you", released on November 18, 2021.