The year he turned 17, he finished fourth in men’s singles at the national team trials that winter and made the national team.
In 2017, he won both the mixed doubles (Kim Ha-na) and men’s doubles (Kim Won-ho) at the Victor Korea Masters.
In 2019, he and Choi Sol-gyu beat the world No. 1 pair in the World Championships men’s doubles and reached the quarterfinals. In 2020, he won bronze in the All England mixed doubles and was suspended from the national team over a dual-contract dispute.
In 2021, he played his first Olympics in Tokyo, going out in the group stage in men’s doubles and in the quarterfinals in mixed doubles. In 2022, while serving in the Korea Armed Forces Athletic Corps, he reached the World Championships quarterfinals.
The breakthrough yearThe year he turned 26, he won both the men’s doubles and the mixed doubles at the World Championships. He became the third Korean, after Park Joo-bong and Kim Dong-moon, to win two events at one World Championships in a year. In October he won bronze in the men’s team event at the Hangzhou Asian Games, and in December he was named BWF Male Player of the Year, won the World Tour Finals and got married.
In 2024, he entered two events at the Paris Olympics and finished without a medal. In early 2025, he re-formed a pair with Kim Won-ho after seven years and reached world No. 1, then won the World Championships and the World Tour Finals and tied the record of 11 titles in a season.
In 2026, he won the All England and the Asian Championships but lost in the semifinals at the World Championships and the Asian Games, taking bronze at both.
Seo Seung-jae (born Sep 4, 1997) made the national team in Dec 2014, the year he turned 17, by finishing fourth at the national team trials, and became known in 2023, the year he turned 26, when he won both the men’s doubles and the mixed doubles at the World Championships. In 2025, the year he turned 28, he reached world No. 1.
Ages are by calendar year (the year minus the birth year), birthdays aside.
Finished fourth in men’s singles at the national team trials, behind Lee Dong-keun, Jeon Hyeok-jin and Heo Kwang-hee, and earned a place on the national team. He was a student at Gunsan Dong High School in North Jeolla Province.
Source 01 · Sports Donga (Korean) · 18-year-old national team member, “Seo Seung-jae’s power” · opens in a new tab The exact date of the trials could not be confirmed.Won two titles at the Victor Korea Masters, an international tournament at Yeomju Gymnasium in Gwangju. In mixed doubles with Kim Ha-na he beat Choi Sol-gyu–Chae Yoo-jung 2-1 (17-21 21-13 21-18), and in men’s doubles with Kim Won-ho he beat Samsung Electro-Mechanics’ Kim Gi-jung–Jung Jae-wook 2-0 (21-15 21-16).
Source 02 · Dong-A Ilbo (Korean) · Seo Seung-jae wins two titles at the Victor Korea Masters · opens in a new tabIn the men’s doubles round of 32 at the World Championships, he and Choi Sol-gyu beat the world No. 1 pair, Marcus Fernaldi Gideon–Kevin Sanjaya Sukamuljo of Indonesia, 2-1 (16-21 21-14 23-21). They lost 0-2 to an Indonesian pair in the quarterfinals and finished the tournament.
Source 04 · Newspim (Korean) · Beat the world No. 1 · opens in a new tabSource 03 · YTN (Korean) · Out in the World Championships men’s doubles quarterfinals · opens in a new tab In mixed doubles (Chae Yoo-jung) he also went out in the quarterfinals at this tournament.Shortly before graduating from Wonkwang University, he signed a provisional contract with Incheon International Airport and, two days later, a formal contract with Samsung Electro-Mechanics, and was suspended from the national team. His appeal was accepted and the penalty was put on hold until after the Tokyo Olympics.
Source 06 · Nocut News (Korean) · Seo Seung-jae stripped of national team status · opens in a new tabSource 07 · Sports Chosun (Korean) · Seo Seung-jae’s severe penalty put on hold · opens in a new tabIn the All England mixed doubles semifinal, he and Chae Yoo-jung lost 1-2 (18-21 21-17 19-21) to the world No. 3 pair, Dechapol Puavaranukroh–Sapsiree Taerattanachai of Thailand, and took bronze.
Source 05 · Kookmin Ilbo (Korean) · Two bronze medals at the All England · opens in a new tabIn his first Olympics, he and Choi Sol-gyu lost their last group match, 1-2 (12-21 21-19 18-21), to the world No. 2 pair, Mohammad Ahsan–Hendra Setiawan of Indonesia, and finished the group stage 1-2.
Source 08 · News1 (Korean) · Choi Sol-gyu–Seo Seung-jae fail to reach the quarterfinals · opens in a new tabIn mixed doubles with Chae Yoo-jung, they lost the quarterfinal 0-2 (9-21 16-21) to the world No. 3 pair, Wang Yilyu–Huang Dongping of China. They had led 13-5 in the second game.
Source 09 · Yonhap News Agency (Korean) · Seo Seung-jae and Chae Yoo-jung out in the quarterfinals · opens in a new tabPlaying men’s doubles with Choi Sol-gyu as a member of the Korea Armed Forces Athletic Corps, he reached the World Championships quarterfinals. They beat Tokyo Olympic gold medalists Lee Yang–Wang Chi-lin of Taiwan in the round of 16 but stamina kept them from the semifinals. His mixed doubles with Chae Yoo-jung also stopped in the quarterfinals.
Source 10 · Badminton News (Korean) · Choi Sol-gyu–Seo Seung-jae win their first title since enlisting · opens in a new tabSource 11 · Yonhap News Agency (Korean) · One silver and one bronze at the World Championships · opens in a new tab The date of the quarterfinal match could not be confirmed in news reports.Won two titles at the World Championships. In mixed doubles with Chae Yoo-jung he beat the world No. 1 pair, Zheng Siwei–Huang Yaqiong of China, 2-1 (21-17 10-21 21-18), winning the event for the first time since Kim Dong-moon–Ra Kyung-min 20 years earlier. In men’s doubles with Kang Min-hyuk he beat Kim Astrup–Anders Skaarup Rasmussen of Denmark 2-1 (14-21 21-15 21-17), the first title in the event since Ko Sung-hyun–Shin Baek-cheol nine years earlier.
Won bronze in the men’s team event at the Hangzhou Asian Games. It was the only medal he won at the Games.
Source 30 · Nocut News (Korean) · Seo Seung-jae and Kim Won-ho’s hard work · opens in a new tabWon the men’s doubles at the World Tour Finals, known as the season finale, with Kang Min-hyuk, beating the world No. 1 pair, Liang Weikeng–Wang Chang of China, 2-0 (21-17 22-20). Earlier, on Dec. 11, he was named BWF Male Player of the Year, the first Korean man to win it since Kim Dong-moon 20 years earlier.
Source 14 · Ilgan Sports (Korean) · Seo Seung-jae, the icon who follows Kim Dong-moon and Lee Yong-dae · opens in a new tabSource 15 · Naver Sports (Chosun Ilbo, Korean) · Seo Seung-jae and Kang Min-hyuk win the season finale · opens in a new tabMarried a spouse one year his junior. On the 22nd, the day before the wedding, Buan County in North Jeolla Province said he had given 5 million won through its hometown donation program, as he is from Buan.
Source 17 · Naver Sports (Hankook Ilbo, Korean) · “Newlywed” Seo Seung-jae · opens in a new tabSource 16 · News1 (Korean) · Seo Seung-jae donates to his hometown Buan · opens in a new tabEntered two events at the Paris Olympics, men’s doubles (Kang Min-hyuk) and mixed doubles (Chae Yoo-jung), won all four group matches over the first two days, all 2-0, and secured quarterfinal places in both. The men’s doubles pair went out in the quarterfinals, and the mixed doubles pair lost the bronze medal match 0-2 (13-21 20-22) to Yuta Watanabe–Arisa Higashino of Japan and finished fourth.
Source 18 · Dong-A Ilbo via Naver (Korean) · Paris Olympics mixed doubles fourth place · opens in a new tabSource 19 · Korea Lecturer News (Korean) · “Shuttlecock Superman” Seo Seung-jae · opens in a new tabRe-formed a men’s doubles pair with Kim Won-ho after seven years, during which the two had gone separate ways since 2018.
Source 24 · News1 via Naver (Korean) · An Se-young and Korean badminton are evolving · opens in a new tabSource 21 · Yonhap News Agency via Naver (Korean) · World Championships men’s doubles title (2025) · opens in a new tabWon the German Open. The pair’s world ranking was No. 55 at the time.
Source 20 · JoongAng Ilbo (Korean) · Orléans Masters semifinal (German Open title mentioned) · opens in a new tabReached No. 1 in the world men’s doubles rankings after winning the Malaysia, German, All England, Indonesia and Japan Opens. It was the first time in nine years, since Lee Yong-dae–Yoo Yeon-seong in November 2016, that a Korean men’s doubles pair was world No. 1.
Source 22 · Wikitree (Korean) · Seo Seung-jae and Kim Won-ho world No. 1 · opens in a new tabWon the World Championships men’s doubles final 2-0 (21-17 21-12) over Chen Boyang–Liu Yi of China. After his 2023 title with Kang Min-hyuk, it was his second straight World Championships title in the event.
Source 21 · Yonhap News Agency via Naver (Korean) · World Championships men’s doubles title (2025) · opens in a new tabWon the World Tour Finals men’s doubles final 2-0 (21-18 21-14) over Liang Weikeng–Wang Chang of China. It was his 11th title of the season, tying the BWF record for most titles in a single season together with An Se-young.
Source 23 · FT Sports (Korean) · Kim Won-ho–Seo Seung-jae win the World Tour Finals · opens in a new tabWon the Malaysia Open men’s doubles for a second year in a row, beating Aaron Chia–Soh Wooi Yik of Malaysia 2-1 (21-15 12-21 21-18) in the final. A shoulder injury from sliding in the quarterfinal led him to withdraw from the next tournament, the India Open.
Source 25 · Newsis via Naver (Korean) · Kim Won-ho–Seo Seung-jae win a second straight Malaysia Open · opens in a new tabSource 26 · Yonhap News Agency via Naver (Korean) · Seo Seung-jae withdraws from the India Open with a shoulder injury · opens in a new tabWon the All England men’s doubles final over Aaron Chia–Soh Wooi Yik 2-1 (18-21 21-12 21-19) for a second straight title. It was the first time in 40 years that a Korean men’s doubles pair won the event two years in a row.
Source 27 · Newsis (Korean) · Asian Championships title · opens in a new tabWon the Badminton Asia Championships men’s doubles final over Kang Min-hyuk–Ki Dong-ju 2-0 (21-13 21-17), his first title at the event.
Source 27 · Newsis (Korean) · Asian Championships title · opens in a new tabHe and Kim Won-ho went for a second straight World Championships men’s doubles title but lost the semifinal 0-2 (17-21 18-21) to Aaron Chia–Soh Wooi Yik of Malaysia and took bronze.
Source 28 · Newsis (Korean) · World Championships bronze (2026) · opens in a new tab Newsis’s “second straight title” refers to the Kim Won-ho–Seo Seung-jae pair, who won in 2025. For Seo himself, after titles in 2023 (Kang Min-hyuk) and 2025 (Kim Won-ho), it was a bid for a third in a row.Playing with Kim Won-ho in the Asian Games men’s doubles semifinal, he lost 0-2 (11-21 14-21) to Daniel Marthin–Leo Rolly Carnando of Indonesia and took bronze.
Source 29 · Dong-A Ilbo via Naver (Korean) · Asian Games men’s doubles bronze · opens in a new tabEND OF SELECTED RECORDSSelected records, 2014–2026 · not a complete list of work. “Key moment” is an editorial label, not a measure of success.
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Sports · South Korea
Sep 4, 1997 —
Ages are counted from the birth year 1997: the year of the event minus 1997, birthdays aside. “Key moment” labels and the connecting story are AgeTrail's editorial reading.
Fact-checked: 2026.09.29 · An independent archive, not affiliated with the person or their agency.