Youngjae debuted with the South Korean boy group Got7 in 2014 with the single Girls Girls Girls from their debut extended play Got It? The album topped Billboard’s World Album Chart and peaked at number two on the Gaon Weekly Albums Chart. That same year, they released their first studio album titled Identify. Aside from being one of Got7’s main vocalists, Youngjae has also written songs for the group and lent his voice to the soundtracks of various television dramas. In 2021, he dropped his debut solo extended play Colors from Ars.
Youngjae landed his first acting role in the 2015 web series Dream Knight, playing himself, along with other Got7 members. In 2021, he joined the main cast of the Netflix sitcom So Not Worth It, where he played the role of a Korean-Australian student named Sam. He then made his musical debut with a leading role in Midnight Sun. Also in 2021, he starred in the web drama Love & Wish.
Youngjae registered as an organ donor in 2020.