Yoon Sang-hyun made his show business debut relatively late at age 32, in the 2005 television series Marrying a Millionaire.

[5] In early 2010, Yoon released the Japanese single Saigo no Ame ("The Last Rain"), which debuted at 11th place on the Oricon Chart.

[8] This was followed by hit TV series Secret Garden with Kim Sa-rang, in which he played the protagonist's cousin and Hallyu star Oska.

[16][17][18][19] In 2013, he returned to the small screen with the popular series I Can Hear Your Voice, playing a well-meaning but bumbling cop-turned-public defender.

[20] He later reunited with the director of I Can Hear Your Voice in the 2014 cable drama Gap-dong, in which he played a detective out to capture a serial killer and clear his father's name.