Kwak Shi-yang made his acting debut in 2014 through the drama film Night Flight, which was followed by an appearance in the SBS series Feel-Good Day. In 2015, he was paired with Kim So-yeon in the fourth season of the MBC reality-variety show We Got Married, which won him the New Star Award at the MBC Entertainment Awards. That same year, he took home an Excellence Award at the KBS Drama Awards for the daily series All Is Well. In 2016, he acted alongside Kim Hee-ae and Ji Jin-hee in the SBS romance drama Second to Last Love, which scored him the New Star Award at the SBS Drama Awards. In 2019, he joined the main cast of MBC’s Welcome 2 Life, which gave him an Excellence Award nomination at the MBC Drama Awards. In 2020, he received another Excellence Award nomination, this time at the SBS Drama Awards for Alice. In 2021, he picked up the Best Character Award at the SBS Drama Awards for his role in Lovers of the Red Sky.

Kwak Shi-yang fulfilled for his mandatory military service prior to his screen debut. He attended Dankook University.