Kwon Soon-woo is a tennis player from South Korea. On November 1, 2021, he reached his career-high ATP singles ranking of World No. 52. On 3 February 2020, he achieved a career-high ATP doubles ranking of World No. 270. After winning the 2018 Asia-Pacific Wildcard Playoff for the main draw of the 2018 Australian Open, Kwon made his tour-level and Grand Slam debut. He debuted in the top 100 on August 5, 2019, at World No. 97, after reaching the quarterfinals of the 2019 Los Cabos Open as a qualifier.
In February 2020, Kwon reached the quarterfinals of four ATP Tour events in a row in Pune, New York, Delray Beach, and Acapulco. As a result, on March 2, 2020, Kwon reached a career-high ranking of 69. Kwon reached the quarter-finals of the ATP 500 event in Acapulco by defeating World No. 24 Duan Lajovi in straight sets. In the quarterfinals, he was defeated by eventual champion Rafael Nadal.
There are no reports of Sonwoo Kwon having a girlfriend or a wife.
Kwon won his first Grand Slam match at the 2020 US Open, defeating wildcard Thai-Son Kwiatkowski. At the 2021 French Open, Kwon reached the third round for the first time in his career, defeating South African Kevin Anderson and Andreas Seppi before losing to another Italian 9th seed and eventual quarterfinalist Matteo Berrettini. Kwon received a second-round bye as a Lucky Loser after Reilly Opelka withdrew at the Eastbourne International despite losing in qualifying. He advanced to the semifinals before losing to Alex de Minaur in the final. Kwon was playing in his first ATP tour semifinal after defeating Ilya Ivashka in the quarterfinals for the eighth time.
Kwon won his first ATP tour level title in Nur-Sultan. He advanced to his second ATP semifinal by defeating qualifier Evgeny Donskoy, third seed Dusan Lajovic, and seventh seed Laslo ere. He advanced to his first ATP tour-level final by defeating home favourite and second seed Alexander Bublik in the semifinal. He won his first ATP title in straight sets over James Duckworth, becoming the first South Korean to do so since Lee Hyung-taik at the Sydney International in 2003, and only the second Korean to win a tour-level title in the Open Era. As a result, on September 27, 2021, he reached a new career high of No. 57.