Soonwoo Kwon was born on December 2, 1997, in Sangju-si, South Korea, to Younghun and Eunmi Kwon. He began playing tennis at the age of 10, having initially wanted to be a professional football player. Kwon’s father is a talented amateur professional tennis player.
After beginning his career on the ITF Futures Circuit, Kwon began to have success on the ATP Challenger Tour in 2017. He reached two finals during that season in Yokohama, Japan, and on home soil in Seoul, South Korea, finishing as the runner-up on both occasions.
Another runner-up placing was achieved the following year in September in Taiwan. Kwon then claimed three Challenger Tour titles between 2019 and 2021. The first two were in Yokohama and Seoul once again in 2019, before also winning the title in Biella. He overcame future Top 20 player Lorenzo Musetti in the final in Biella.
The South Korean made his Grand Slam main draw appearance at the 2018 Australian Open. He lost in the first round there and at his following four Grand Slams. That streak was broken at the 2020 US Open with a victory against Sebastian Korda, before losing to Denis Shapovalov.
2021 saw Kwon win his maiden ATP Tour title at the Astana Open. He progressed to the final with victories against Daniel Elahi Galan, Lorenzo Musetti, Laslo Djere, and Alexander Bublik. He then defeated James Duckworth 7-6, 6-3 in the final to reign supreme in Kazakhstan.
Kwon also made his first appearance in the third round of a Grand Slam at the 2022 Roland Garros. He achieved this with triumphs against two-time Grand Slam runner-up Kevin Anderson and Andreas Seppi, before exiting to Matteo Berrettini.
The South Korean was consistent in 2022, without having any particularly outstanding results. Kwon did not make any ATP finals or get past the second round of any of the Grand Slams. However, he still won twenty matches and finished the season inside the Top 100.
Kwon started 2023 very strongly by winning another ATP title at the Adelaide International. As a lucky loser, he overcame Tomas Machac, Pablo Carreno Busta, Mikael Ymer, and Jack Draper to make the final. Kwon then won a thrilling final 6-4, 3-6, 7-6 against Roberto Bautista Agut to lift the trophy. The South Korean was sidelined for six months after this. He returned using a protected ranking at the 2023 US Open and 2024 Australian Open.
