Seo Seung-jae

2.1. Junior Career

During his junior career, Seo Seung-jae demonstrated considerable talent and potential. In 2012, he earned a bronze medal in the mixed team event at the BWF World Junior Championships held in Chiba, Japan. The following year, at the 2013 World Junior Championships in Bangkok, Thailand, he secured a gold medal in the mixed team event and a bronze medal in the boys' doubles. He also participated in the Badminton Asia Junior Championships, winning silver medals in the mixed team event in 2013 and 2014. In 2015, he achieved another silver medal in the boys' singles at the Asian Junior Championships in Bangkok, alongside a mixed team silver. In 2014, Seo also represented South Korea at the 2014 Summer Youth Olympics in Nanjing, China, where he finished ninth in the singles event.

2.2. Early Senior Career and International Debut

Seo Seung-jae transitioned to the senior circuit with notable early successes. In 2017, as a student of Wonkwang University, he competed in the Summer Universiade in Taipei, Taiwan. There, he clinched the gold medal in men's doubles, partnering with Kim Jae-hwan. The same year, he contributed significantly to the Korean national team's victory at the 2017 Sudirman Cup in Gold Coast, Australia, helping them secure their fourth trophy in the prestigious mixed team championship.

He continued to establish himself on the BWF World Tour and Grand Prix circuits. In 2019, partnering with Choi Sol-gyu in men's doubles at the Hong Kong Open, he achieved a significant upset. The pair defeated world number 4 Takeshi Kamura and Keigo Sonoda in the opening round and overcame world number 6 Hiroyuki Endo and Yuta Watanabe in the semifinals. In the final, they triumphed over world number 2 Mohammad Ahsan and Hendra Setiawan to claim the title from an unseeded position.

Seo Seung-jae made his Olympic debut at the 2020 Summer Olympics in Tokyo, Japan. He competed in men's doubles with Choi Sol-gyu and in mixed doubles with Chae Yoo-jung, reaching the group stage and quarter-finals, respectively. Following the Olympics, in 2021, he participated in the 2021 Sudirman Cup and the Thomas Cup, although the Korean team did not secure medals in these events. He also played in two BWF World Tour tournaments that year: the 2021 Indonesia Masters and the 2021 Indonesia Open.

2.3. Breakthrough Year: 2023 World Championships and World Tour Finals

The year 2023 marked a pivotal breakthrough for Seo Seung-jae, as he achieved unprecedented success on the international stage. At the 2023 BWF World Championships in Copenhagen, Denmark, he made history by winning two gold medals. In mixed doubles, partnering with Chae Yoo-jung, he defeated the world number one pair Zheng Siwei and Huang Yaqiong of China with a score of 21-17, 10-21, 21-18. This victory was particularly significant as he had an unfavorable head-to-head record against the Chinese duo, having lost all nine previous encounters. In men's doubles, alongside Kang Min-hyuk, he overcame the home favorites Kim Astrup and Anders Skaarup Rasmussen of Denmark with a score of 14-21, 21-15, 21-17. This achievement made him the first South Korean player in 24 years to secure two gold medals in a single edition of the BWF World Championships and only the fifth player in history to achieve this feat across two different categories.

Following his World Championships triumph, Seo continued his stellar performance. He secured his first-ever Super 1000 title at the China Open with Chae Yoo-jung, defeating Zheng Siwei and Huang Yaqiong in the quarterfinals for their second consecutive victory over the reigning world champions. His outstanding achievements throughout 2023 were recognized with the prestigious Male Player of the Year award. He capped off the year by winning his first BWF World Tour Finals title in men's doubles with Kang Min-hyuk, defeating the world number one Chinese pair Liang Weikeng and Wang Chang 21-17, 22-20, solidifying his status as an annual champion.

2.4. Recent Activities and Partnership Changes

In 2022, Seo Seung-jae officially began a new men's doubles partnership with Kang Min-hyuk. The newly formed duo quickly made an impact, winning the Korea Open by defeating several higher-ranked pairs, including Satwiksairaj Rankireddy and Chirag Shetty, Mohammad Ahsan and Hendra Setiawan, and Fajar Alfian and Muhammad Rian Ardianto in the final. Despite this early success, their results in 2022 were somewhat inconsistent, with early exits at tournaments like the Japan Open, Malaysia Open, and French Open. Meanwhile, Seo resumed his mixed doubles partnership with Chae Yoo-jung, reaching the semi-finals at the 2022 Indonesia Masters and winning the Australian Open against South Korean teammates Jeong Na-eun and Kim Won-ho. They also reached the semi-finals at the 2022 Indonesia Open and the quarter-finals at the World Championships.

The 2024 season saw Seo Seung-jae continue his strong performance, winning the India Open in men's doubles with Kang Min-hyuk. They also reached the finals of the Japan Open, Korea Open, and Hong Kong Open, winning the latter. After the China Open in September, his partnership with Kang Min-hyuk came to a temporary halt as Kang commenced his mandatory military service. This led Seo to explore new partnerships.

In November 2024, he partnered with Ki Dong-ju at the Korea Masters, reaching the semi-finals where they narrowly lost to fellow South Koreans Jin Yong and Kim Won-ho. Shortly after, he began pairing with Jin Yong for the Japan Masters and China Masters. In their second tournament together, the China Masters, Seo and Jin achieved a significant victory, defeating top pairs like Fajar Alfian/Muhammad Rian Ardianto, Takuro Hoki/Yugo Kobayashi, and Satwiksairaj Rankireddy/Chirag Shetty to claim the title.

Beginning the 2025 season, Seo Seung-jae entered the Malaysia Open and India Open with Kim Won-ho. Despite the new pairing, they continued his success, winning the Malaysia Open by defeating top seeds like Liang Weikeng/Wang Chang and Satwiksairaj Rankireddy/Chirag Shetty, marking his second consecutive top-tier tournament win with a new partner. They were runners-up at the India Open. He then won the Thailand Masters with Jin Yong, further demonstrating his versatility and adaptability with different partners.

3.1. World Championships

Seo Seung-jae achieved a historic double gold at the 2023 BWF World Championships.

Men's doubles

Year	Venue	Partner	Opponent	Score	Result
2023	Royal Arena, Copenhagen, Denmark	South Korea Kang Min-hyuk	Denmark Kim Astrup Denmark Anders Skaarup Rasmussen	14-21, 21-15, 21-17	Gold

Mixed doubles

Year	Venue	Partner	Opponent	Score	Result
2023	Royal Arena, Copenhagen, Denmark	South Korea Chae Yoo-jung	China Zheng Siwei China Huang Yaqiong	21-17, 10-21, 21-18	Gold

3.2. Multi-sport Events

Seo has also medaled in several major multi-sport competitions.

Sudirman Cup

Year	Venue	Event	Result
2017	Gold Coast, Australia	Mixed team	Gold
2021	Vantaa, Finland	Mixed team	Bronze
2023	Suzhou, China	Mixed team	Silver

Asian Games

Year	Venue	Event	Partner	Opponent	Score	Result
2022	Binjiang Gymnasium, Hangzhou, China	Mixed doubles	South Korea Chae Yoo-jung	China Zheng Siwei China Huang Yaqiong	21-13, 15-21, 16-21	Bronze
2022	Binjiang Gymnasium, Hangzhou, China	Men's team	N/A	N/A	N/A	Bronze

Asia Championships

Year	Venue	Event	Partner	Opponent	Score	Result
2024	Ningbo Olympic Sports Center Gymnasium, Ningbo, China	Mixed doubles	South Korea Chae Yoo-jung	China Feng Yanzhe China Huang Dongping	21-13, 15-21, 14-21	Silver

Asia Team Championships

Year	Venue	Event	Result
2018	Alor Setar, Malaysia	Men's team	Bronze
2024	Selangor, Malaysia	Men's team	Bronze

Summer Universiade

Year	Venue	Event	Partner	Opponent	Score	Result
2017	Taipei Gymnasium, Taipei, Taiwan	Men's doubles	South Korea Kim Jae-hwan	Japan Katsuki Tamate Japan Kenya Mitsuhashi	21-12, 21-19	Gold

World Junior Championships

Year	Venue	Event	Partner	Opponent	Score	Result
2012	Chiba Port Arena, Chiba, Japan	Mixed team	N/A	N/A	N/A	Bronze
2013	Hua Mark Indoor Stadium, Bangkok, Thailand	Mixed team	N/A	N/A	N/A	Gold
2013	Hua Mark Indoor Stadium, Bangkok, Thailand	Boys' doubles	South Korea Choi Jong-woo	China Huang Kaixiang China Zheng Siwei	11-21, 13-21	Bronze

Asian Junior Championships

Year	Venue	Event	Partner/Opponent	Score	Result
2013	Kota Kinabalu, Malaysia	Mixed team	N/A	N/A	Silver
2014	Taipei Arena, Taipei, Taiwan	Mixed team	N/A	N/A	Silver
2015	CPB Badminton Training Center, Bangkok, Thailand	Boys' singles	China Lin Guipu	16-21, 11-21	Silver
2015	CPB Badminton Training Center, Bangkok, Thailand	Mixed team	N/A	N/A	Silver

3.3. BWF World Tour and Grand Prix

The BWF World Tour, launched in 2018, is a series of elite badminton tournaments sanctioned by the Badminton World Federation (BWF), categorized into World Tour Finals, Super 1000, Super 750, Super 500, Super 300, and the BWF Tour Super 100. The BWF Grand Prix, active from 2007 to 2017, consisted of two levels: Grand Prix and Grand Prix Gold. Seo Seung-jae has achieved a total of 18 titles and 16 runner-up finishes on the BWF World Tour, and 4 titles and 3 runner-up finishes on the BWF Grand Prix circuit.

Men's doubles (11 titles, 6 runners-up on BWF World Tour; 1 title, 2 runners-up on BWF Grand Prix)

Mixed doubles (7 titles, 10 runners-up on BWF World Tour; 3 titles, 1 runner-up on BWF Grand Prix)

3.4. Other International Competitions

Seo has also found success in other international circuits, including the BWF International Challenge/Series.

Men's doubles (2 titles)