Kim Young-dae appeared in several web dramas at the start of his acting career. In 2018, he made his small screen debut in a KBS2 Drama Special episode titled The Time Left Between Us. In 2019, he starred in the webtoon-based MBC series Extraordinary You, which won the Drama of the Year at the MBC Drama Awards. He also earned a Best New Actor nomination at the ceremony for his work in the series. In 2020, he became part of the top-rating SBS drama Penthouse and also appeared in its second and third seasons. His performance in the series scored him Best New Actor nominations at the 57th Baeksang Arts Awards and the SBS Drama Awards. Also in 2020, he joined the main cast of the KBS2 drama Cheat on Me, If You Can, in which he received the Netizen Award at the KBS Drama Awards.

Kim Young-dae has a younger sister. He attended Fudan University in China. He can speak Chinese and can also play the piano and guitar.