Lee Tae-hwan was launched as part of the five-member actor group 5urprise in September 2013. They made their acting debut in the web series After School: Lucky or Not and released the single Hey U Come On for the drama’s soundtrack. The group also have three single albums together. In March 2020, the group’s five members parted ways with Fantagio after their contracts with the agency ended.

Lee Tae-hwan’s work as a solo artist includes the 2014 series Pride and Prejudice, which was nominated for Drama of the Year at the MBC Drama Awards. In 2016, he became part of the fantasy series W–Two Worlds, which earned him a Best New Actor nomination at the MBC Drama Awards. He also starred in the 2016 MBC weekend drama Father, I’ll Take Care of You, which was followed by a role in KBS2’s top-rating series My Golden Life in 2017. He was nominated for Best New Actor at the KBS Drama Awards for his work in the latter. In 2018, he acted alongside Park Seo-joon and Park Min-young in the hit tvN romantic comedy What’s Wrong with Secretary Kim.

Lee Tae-hwan majored in acting at the Sungkyunkwan University.