In 2023, Lee won the gold medal in the halfpipe at the FIS Freestyle Ski and Snowboarding World Championships 2023 in Bakuriani, Georgia. The 16-year-old was the first South Korean to win a gold medal in any skiing or snowboarding discipline and also the youngest male snowboard gold medalist in world championship history.[2][3]
At the 2024 Winter Youth Olympics in Gangwon Province, South Korea, Lee grabbed two gold medals in snowboard men's slopestyle and halfpipe.[4][5] He became the first South Korean to win a gold medal in snowboarding at any Winter Olympic competition.