Aryna Siarhiejeŭna Sabalenka (born 5 May 1998) is a Belarusian professional tennis player. She is currently the world No. 1 in women's singles by the WTA, and is a former world No. 1 in doubles. Sabalenka has won 21 WTA Tour-level singles titles, including four majors – two each at the Australian Open and the US Open – as well as nine WTA 1000 events. She has also won six doubles titles, including the 2019 US Open and 2021 Australian Open, both partnering Elise Mertens.

Sabalenka came to prominence in 2017 when, together with Aliaksandra Sasnovich, she led the Belarus Fed Cup team to a runner-up finish even though both were ranked outside the top 75 at the time. She finished 2018 and 2019 ranked No. 11 in the world in singles. Following two major singles semifinal appearances in 2021, Sabalenka rose to the world No. 2 ranking but struggled to maintain that success in 2022 consistently. In 2023, she won her first major singles title at the Australian Open and obtained the world No. 1 ranking, being named the ITF World Champion for the season.

Sabalenka successfully defended her Australian Open title and won the US Open the following year, clinching the year-end No. 1 ranking. In 2025, she defended her title at the US Open, and finished as the runner-up at the Australian and French Opens.

Sabalenka began playing doubles regularly in 2019. With Mertens as her partner, she found instant success by winning the Sunshine Double (Indian Wells and Miami) that same year. After the US Open doubles title later in the season, she qualified for the WTA Finals for the first time. With the 2021 Australian Open doubles title, Sabalenka became the world No. 1 in the discipline, after which she shifted to playing exclusively singles.

Sabalenka has an aggressive style of play, often accumulating high numbers of winners and unforced errors. With her height, she also displays powerful serves.

Sabalenka was born in Minsk, the capital of Belarus. Her father, Sergey (d. 2019), was an ice hockey player. Sabalenka started playing tennis by chance. She said, "One day, my dad was just driving me somewhere in the car, and he saw tennis courts on the way. So he took me to the courts. I liked it and enjoyed it, and that's how it was. That's how it started." She began training at the National Tennis Academy in Minsk when it opened in 2014. In 2015, the Belarusian Tennis Federation persuaded Sabalenka and her team to focus on playing low-level professional events instead of junior tournaments, even though she was still eligible to compete at the junior level.

Sabalenka had a late start on the ITF Junior Circuit, instead competing on the U14 and U16 Tennis Europe tours at a younger age. She did not compete in the main draw of any ITF events until 2013 at the low-level Grade-4 Tallink Cup in Estonia at the age of 15. She never played in the junior Grand Slam tournaments or any other high-level Grade-A and Grade-1 events. Without the higher point levels from these bigger tournaments, she had a career-high ranking of just No. 225. Sabalenka won her first ITF title in doubles at the lowest-level Grade-5 Alatan Tour Cup in Belarus in late 2013 with compatriot Vera Lapko as her partner. In 2014, she excelled at Grade 4 events. She reached her first singles final at the Estonian Junior Open in June and won her first singles title at the MTV Total Junior Cup in Finland in October. At the end of the season, Sabalenka defended her Alatan Tour Cup doubles title, this time with compatriot Nika Shytkouskaya, and also won the singles title. She only played in one tournament in 2015, the European Junior Championships. As a Grade B1 event, this was the highest-level junior tournament she played in. She lost in the second round to top seed Markéta Vondroušová.

Sabalenka began playing on the ITF Women's Circuit in 2012, even before she competed on the ITF Junior Circuit. Her first five tournaments were in her hometown of Minsk and spread out over two years, but she did not win a main draw match in any of them. She won her first professional match at the very end of 2014 in Istanbul. The following season in October, she won her first two titles in back-to-back weeks in Antalya, both at the $10k level. Sabalenka also won a $25k title the last week of the year. This title put her into the top 300 WTA rankings for the first time at the start of 2016. That year, she made her Fed Cup debut in April, losing her only match. She also won her two biggest titles to date at the $50k level. The first in Tianjin put her into the top 200 in May and the second in Toyota in November helped her finish the year ranked at No. 137 in the world.