Ong Seong-wu (Hangul: 옹성우, born August 25, 1995) is a South Korean singer and actor. He is known for his participation in the survival reality show Produce 101 Season 2, where he finished in fifth place, and is a former member of the show’s derivative boy group Wanna One.
Ong Seong-wu was born in Incheon, South Korea. He then attended Hanlim Multi Art School, graduating in 2014. He subsequently graduated from Dong Seoul University as a performing arts major.
Ong participated in Produce 101 (season 2). In the finale, he finished in fifth place with 984,756 votes, securing him a spot as a member of Wanna One.
It was reported that Ong had taken part in a short film project, Short Film Project: Beginning, prior to his participation in Produce 101. The short film, titled Seong-wu Is Alright, was released on June 19. Additionally, he also made a special appearance on the mobile drama Idol Fever, which aired between July 7 to July 17, 2017.
Ong debuted as a member of the project group Wanna One on August 7, 2017. 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 has also served as a special emcee on music show broadcasts for M Countdown and Inkigayo. On September 21, it was announced that he, together with fellow group mate Kang Daniel, were cast for the pilot episode of the variety show Master Key. He was later confirmed as a fixed cast member. His appearance on the show garnered positive reactions from media outlets, receiving praise for his skilful deception of his cast mates in the psychological game-style show to net the show’s biggest win thus far. In November, Ong featured in singer Huh Gak’s music video for his digital single “Only You”.
Ong was named one of the main emcees of Show! Music Core in February 2018. He left his position in September 2018. He also became a cast member of the reality show Law of the Jungle Sabah. The show aired from July 27, 2018 to September 21, 2018.
Ong concluded his contract with Wanna One on December 31, 2018, although he would still appear with the group until its official farewell concerts on January 24–27, 2019.
In 2019, Ong was casted as the male lead in the JTBC youth drama The Moment of 18, alongside Kim Hyang-gi and Shin Seung-ho.