Jeļena "Aļona" Ostapenko (born 8 June 1997) is a Latvian professional tennis player. She has career-high rankings of world No. 5 in singles and No. 4 in doubles by the WTA. Ostapenko has won nine WTA Tour-level singles and eleven doubles titles, including a singles major at the 2017 French Open and a doubles major at the 2024 US Open, partnering Lyudmyla Kichenok. She is the first Latvian to win a major in singles or in doubles. Ostapenko has also won 15 singles titles and 15 doubles titles on the ITF Women's Circuit, and the junior singles event at the 2014 Wimbledon Championships. She is a member of the Latvia Billie Jean King Cup team.