In 2013, at the age of eighteen, Lee Tae-hwan made his official acting debut in the short TV series titled After School: Lucky or Not together with the members of 5urprise.

[2] He next starred in High School King of Savvy, portraying an ice hockey player;[3] and also played the younger version of Lee Deok-wa in the 2-episode SBS drama Wonderful Day in October.

[10] Lee also made his big screen debut in the Su Saek, a film depicting about the friendship among young men.

[14] In 2018, Lee was cast in tvN's romantic comedy drama What's Wrong with Secretary Kim, playing a famous author.

[15] In 2019, Lee starred in SBS youth drama Farmers' Academy, playing a first year student at the Department of Food crops.