Kim Young-kwang started his entertainment career as a model before transitioning into acting in 2008 through the KBS2 series The World They Live In. In 2013, he became part of the hit KBS2 medical series Good Doctor, which gave him a Best New Actor nomination at the KBS Drama Awards. In 2014, he starred in the romantic comedy film Hot Young Bloods, which earned him the Best New Actor trophy at the 22nd Korea Culture and Entertainment Awards. That same year, he joined the main cast of the SBS series Pinocchio, which scored him the New Star Award at the SBS Drama Awards. In 2016, he was paired with Su Ae in KBS2’s The Man Living in Our House, which was followed by another leading role in MBC’s Lookout in 2017. In 2018, he reunited with his Hot Young Bloods co-star Park Bo-young in the romantic comedy film On Your Wedding Day, which won him Best New Actor at the 55th Baeksang Arts Awards. In 2019, he was nominated for a Top Excellence Award at the SBS Drama Awards for The Secret Life of My Secretary.

Kim Young-kwang attended Hanyang University. He enlisted for his mandatory military service in December 2013 and was discharged in June 2014, as he was only required to serve the military for six months due to his father being a veteran of the Vietnam war.