Yoon Doo-joon debuted as the leader of the South Korean boy group BEAST in 2009. They released their first extended play Beast Is the B2ST in October of that year. In March 2011, they made their Japanese debut with the single Shock, which was followed by the release of their first full-length Korean album titled Fiction and Fact in May. The album topped the Gaon Album Chart and sold over 142,000 copies by the end of 2011, making it the fifth best-selling album in South Korea of that year. In 2017, the group changed their name to Highlight after they moved to a new label. In July 2020, Yoon Doo-joon released his first solo album called Daybreak.

Yoon Doo-joon debuted as an actor with recurring roles in the 2010 MBC sitcoms More Charming by the Day and All My Love, which won him the Rookie Comedy Award at the MBC Entertainment Awards. In 2013, he landed his first leading role in the tvN series Let’s Eat and returned for its second and third seasons aired in 2015 and 2018.

Yoon Doo-joon began his mandatory military service on August 24, 2018 and was discharged on April 10, 2020.