Jeļena Ostapenko, also known as Aļona Ostapenko (born 8 June 1997), is a Latvian professional tennis player. On 12 June 2017, she reached her best singles ranking of world number 12 in the Women's Tennis Association (WTA), and she peaked at world number 33 in the WTA doubles rankings on 1 May 2017.
At the 2017 French Open, Ostapenko became the first player from Latvia to win a Grand Slam tournament, and the first unseeded player to win the French Open since 1933. In addition to her singles career, she has also played as a member of Latvia's Fed Cup team. She has won seven singles and eight doubles titles on the ITF tour, and also won the Junior singles event at the 2014 Wimbledon Championships. Ostapenko is known for her highly aggressive playing style, including powerful inside-out groundstrokes and a tendency to aim for the lines.