Seo Seung-jae is a South Korean badminton player. He is the first South Korean player in 24 years to have won two gold medals in a single edition of the BWF World Championships, by winning the mixed and men's doubles event at the 2023 BWF World Championships, partnering with Chae Yoo-jung and Kang Min-hyuk respectively. He competed at the 2017 Sudirman Cup and helped the Korean national team to its fourth trophy.

The BWF World Championships, formerly known as IBF World Championships, and also known as the World Badminton Championships, is a badminton tournament sanctioned by Badminton World Federation (BWF). The tournament is one of the most prestigious in badminton, offering the most ranking points, together with the Summer Olympics badminton tournaments which was introduced in 1992. The winners of this tournament are also crowned as "World Champions" of the sport, and are awarded a gold medal.