Jeļena "Aļona" Ostapenko, born on 8 June 1997, is a professional tennis player from Latvia. She has achieved career-high WTA rankings of world No. 5 in both singles and doubles. Ostapenko made history as the first Latvian to win a Grand Slam title in singles and doubles, excluding mixed doubles. Her notable achievements include winning the 2017 French Open singles title, becoming the first unseeded player to claim the Roland Garros championship since 1933, and securing the doubles title at the 2024 US Open alongside Ukrainian player Lyudmyla Kichenok.

In her career, Ostapenko has claimed seven additional singles titles and eight doubles titles on the WTA Tour, along with fifteen singles and fifteen doubles titles on the ITF Women's Circuit. She also won the junior singles title at Wimbledon in 2014 and represents Latvia in the Fed Cup. Known as an aggressive baseliner, her playing style is characterized by flat, powerful forehands and backhands, often aiming to finish points quickly with strong groundstrokes and volleys. Her high-risk approach results in both a high number of winners and unforced errors, and while her forehand and backhand are her strengths, her serve remains inconsistent, particularly her second serve. Ostapenko has been coached by her mother throughout her career, with additional guidance from several renowned coaches, including Marion Bartoli and Anabel Medina Garrigues.