Marta Kostyuk is a Ukrainian professional tennis player born on June 28, 2002, in Kyiv. At age 23, she plays right-handed, stands 5-foot-9, and holds a career-high WTA singles ranking of No. 16 achieved on June 17, 2024. She is currently ranked around No. 23-27 and is Ukraine's No. 2 player.[1][2][4] From a tennis family—her mother Talyna Beyko was a pro player—Kostyuk began competing young. In 2017, at 14, she won the Australian Open girls' singles title and later that year claimed her first ITF pro title in Dunakeszi, Hungary, becoming Ukraine's youngest pro winner. She also secured the US Open girls' doubles title and the ITF Junior Masters, peaking at junior world No. 2.[1][2][3] Turning pro, she debuted at the 2018 Australian Open as the youngest main-draw entrant, upsetting Peng Shuai and breaking into the WTA Top 200. Early highlights included Fed Cup wins and ITF successes. She broke into the Top 100 in 2020 after ITF finals.[1][3] On the WTA Tour, Kostyuk won her maiden singles title at the 2023 ATX Open, dedicating it to Ukraine amid the war and refusing a handshake with her Russian opponent. She has two doubles titles: 2022 Portoroz and 2023 Birmingham. In 2024, she reached her first Grand Slam quarterfinal at the Australian Open, WTA 500 finals in San Diego and Stuttgart, a WTA 1000 semifinal at Indian Wells, and Roland Garros Round of 16. She earned five Top 10 wins, debuted in the Top 20 on May 6, and ended the year at No. 18, plus Paris Olympics quarterfinals and Forbes 30 Under 30 recognition.[1][2][3][5] In 2025, she posted a 26-20 singles record, reached US Open Round of 16, and three WTA 1000 quarterfinals. She started 2026 strongly, finishing runner-up in Brisbane—her fourth career final—while training in Monaco and Kyiv under coach Sandra Zaniewska.[1][4][5]