Kim Ryeo Wook, born on June 21, 1987, more commonly credited as Ryeo Wook, is a Korean singer, dancer, occasional actor, and the third youngest member of Super Junior. He is recognized by his fellow members as the "eternal magnae" (eternal youngest) of the group, as well as one of the three most vocally powerful in the group (Super Junior-K.R.Y.). Even before Kyu Hyun's addition to the group in May 2006, Ryeo Wook commonly called himself the youngest despite being a few months older than Ki Bum. Ryeo Wook is currently studying at Inha University. He is also one of the first Korean artists to appear on Chinese postage stamps.

Kim Ryeo Wook was discovered through the CMB Youth Chin Chin Festival in 2004 and signed a contract with SM Entertainment soon afterwards after impressing judges with his singing talent. Trained in areas of singing, dancing, and acting, Ryeo Wook placed particular efforts into his vocal training and music composition as he was most concerned in those areas.