Lee Jae-wook debuted as an actor in the 2018 tvN series Memories of the Alhambra. His career quickly picked up after he played one of the main characters in tvN’s Search Query: WWW the following year. He then appeared in the action-war film The Battle of Jangsari. Later in 2019, he starred in the MBC fantasy rom-com Extraordinary You, which won him Best New Actor at the MBC Drama Awards. He was also nominated for Best New Actor at the 56th Baeksang Arts Awards for his work in the series. In 2020, he played a supporting role in the JTBC drama I’ll Find You on a Beautiful Day. That same year, he was cast in his first leading role in KBS2’s Do Do Sol Sol La La Sol, opposite Go Ara. His performance in the series gave him an Excellence Award at the KBS Drama Awards.

Lee Jae-wook attended Chung-Ang University. In February 2024, it was confirmed that he is dating Karina of the South Korean girl group Aespa.