Kim Dae-myung began his acting career on stage before becoming known as a TV and movie star. He made his film debut in 2006 through Puzzle and also appeared in the short films The Lost Thing and Blue Ocean in 2010. His career breakthrough came in 2014 when he was cast in the tvN workplace drama Misaeng, which won him an Excellence Award at the 8th Korea Drama Awards. His performance in the series also earned him a Best New Actor nomination at the 51st Baeksang Arts Awards. In 2016, he joined the main cast of the KBS2 sitcom The Sound of Your Heart. In 2017, he acted alongside Choi Jin-woong in the psychological thriller film Bluebeard, which scored him several Best Supporting Actor nominations. In 2020, he played one of the main characters in the hit tvN series Hospital Playlist and reprised his role in its second season, which aired the following year. Later in 2021, he received the Jury’s Special Award at the 41st Golden Cinema Film Festival for his work in the film Skipping Stones.

Kim Dae-myung studied acting at Sungkyunkwan University.