Ji So-Yun (born 21 February 1991) is a South Korean football player who is currently playing for FA WSL's Chelsea LFC, and in the Korea Republic women's national football team. On 30 November 2006, she was the youngest goalscorer (15 years, 282 days) of the Korea Republic women's national football team after scoring two goals against Chinese Taipei in the 2006 Asian Games. She is the first South Korean football player to score a hat-trick in the finals of FIFA competitions.

In November 2013 Ji was subject to a transfer bid from Chelsea LFC of the English FA WSL. She agreed a two year contract in January 2014. When the transfer was officially confirmed later that month, Chelsea coach Emma Hayes said of Ji: "She is one of the best midfielders in the world and our fans will love her."