[3] He started his path as an idol after he passed the JYP Entertainment's Global Audition in the United States to begin his trainee life in South Korea in 2015.

[6][full citation needed] He participated on the program along with Brand New Music representative trainees Park Woo-jin, Im Young-min and Kim Dong-hyun.

In the finale, he finished in third place with 1,102,005 votes, securing him a spot as a member of the boy band which was named Wanna One.

[21] After his debut in Wanna One, Lee had been actively released his own songs under his label, Brand New Music.

[24] In January 2019, Lee collaborated with fellow labelmate Park Woo-jin and released a single titled "Candle".

Lee is set to make his acting debut as the male lead Dong Jin-woo in SBS's mobile platform Mobidic short drama called Mon Chouchou Global House.

[34][full citation needed] On December 16, 2020 it was confirmed that Lee would be producing songs for Mnet's audition show CAP-TEEN.

[citation needed] In April 2019, Lee was selected for his first solo endorsement deal as a campaign model of Coca-Cola Korea beverage brand, Fanta pineapple flavor.