Ryu Sung-hyun (born 22 October 2002) is a South Korean artistic gymnast. He won the gold medal in the floor exercise at the 2019 Junior World Artistic Gymnastics Championships held in Győr, Hungary. In 2020, he won the gold medal in the floor exercise in Melbourne, Australia as part of the FIG Artistic Gymnastics World Cup series. He competed for the Korean team at the 2020 Summer Olympics in Tokyo, Japan.
