He debuted as an idol in the six-member group B.A.P under TS Entertainment, where he served as the main vocalist from 2012 to its dissolution in 2019.

[1] In his second year of middle school, Yoo sang during a talent show with a group of friends; he described the cheers for an encore "only for me".

After spending tens months in communication, he became a trainee under JYP Entertainment and was slated to debut in a group at the time.

[9] In August and December 2018, Yongguk and Zelo left the group and record label following the expiration of their contracts, respectively.

Yoo was cast in his first major television role in the KBS drama Woman of 9.9 Billion which began airing in November.

[20] In March 2020, fans speculated that Yoo had terminated his contract with DMost Entertainment after his profile had been taken down from the company's official website.

In June 2020, it was revealed that Yoo had been cast in tvN's historical comedy drama, Mr. Queen through an official audition process.

[25] Yoo has since continued developing his acting career, taking on the lead role of Na A-reum in tvN's Our Beautiful Summer upon completing his military service.

[26] Yoo also made his debut as a musical actor in 2024 through Buchihanan (부치하난) where he was cast in the lead role of Nu-ri.