Kateřina Siniaková

Kateřina Siniaková (Czech pronunciation: [ˈkatɛr̝ɪna ˈsɪɲakovaː]; born 10 May 1996) is a Czech professional tennis player. She is a former world No. 1 in women's doubles, and has a career-best best singles ranking of world No. 27 by the WTA, achieved in June 2024.

Siniaková is a ten-time major champion in women's doubles and one-time champion in mixed doubles. She won seven of her major titles in her longtime partnership with compatriot Barbora Krejčíková, with whom she completed the career Golden Slam. She has won three other women's doubles majors, partnering Coco Gauff and Taylor Townsend, and one in mixed doubles partnering Sem Verbeek. Siniaková became world No. 1 for the first time in October 2018 and has held the top ranking in doubles for a total of 180 weeks, the third-longest total since the beginning of the WTA rankings. Siniaková has won 34 doubles titles on the WTA Tour, including the 2021 WTA Finals and seven WTA 1000 events.

In singles, Siniaková has won five career titles. Her best singles major result was at the 2019 French Open, upsetting world No. 1 Naomi Osaka en route to the fourth round; she has reached the third round at seven other major tournaments.

Siniaková was part of the Czech team that won the 2018 Fed Cup, and has won two Olympic gold medals: in women's doubles at the 2020 Tokyo Olympics with Krejčíková, and in mixed doubles at the 2024 Paris Olympics with Tomáš Macháč.