Lee Sung-hyun (Korean: ???; born January 10, 1991) is a South Korean kickboxer who competes in the lightweight, welterweight and middleweight divisions.
Known for his speed and sophisticated combinations, Lee debuted in K-1 in March 2009 and further established himself by winning the RISE Korea Super Lightweight Championship in June 2011.
He then went on compete regularly for RISE in Japan and had a breakout year in 2013 by winning the K-1 Korea MAX 2013 Tournament and the RISE lightweight title.
As of April 2013, Lee is ranked the #4 lightweight in the world by LiverKick.com.