Oleksandra Denysivna Oliynykova (; born 3 January 2001) is a Ukrainian professional tennis player. She has career-high rankings of world No. 66 in singles, achieved on 16 March 2026, and No. 663 in doubles, achieved on 6 May 2024. She has won three WTA 125 singles titles as well as 10 singles and two doubles titles on the ITF Women's Circuit.
Oliynykova was born and raised in Kyiv. At the age of eight, she and her family moved to Odesa. In 2011, when Oliynykova was 10 years old, she and her family fled to Croatia after her father publicly criticized the presidency of Viktor Yanukovych. Her family was able to return to Ukraine after the Revolution of Dignity in 2014, which saw the removal of Yanukovych from office.
Oliynykova continued to live and train in Zagreb, but as of 2026 was living and training in Kyiv, describing herself as the only Ukrainian professional tennis player to continue training in Ukraine following the Russian invasion of Ukraine in 2022.
Oliynykova began representing Ukraine in 2022. That October, she won her second ITF title at the W15 tournament in Heraklion.
In August, she won the W35 tournament in Køge, defeating Deborah Chiesa in the final. Later that month, she reached the final of the W35 ÃÂiriac Foundation Trophy in BistriÃÂa, but lost to Patricia Maria ÃÂig. In October, she won her second title of the year at the W35 tournament in Heraklion. The following month, she qualified for the main draw of the Copa LP Chile and defeated Martina Capurro Taborda in the first round for her first WTA 125-level victory.
In May, she won the W35 Fortevillage ITF Trophy in Santa Margherita di Pula, but later lost her ranking points and was fined by the WTA for not withdrawing from the qualifiers of the L'Open 35 de Saint-Malo, for which she was registered as an alternate, in time. The following week, however, she won another title in Santa Margherita di Pula. Later that month, she also won the W50 tournament in Portoroà ¾, defeating Kajsa Rinaldo Persson in the final for her biggest title to date.
In September, Oliynykova won her first WTA 125 title at the Tolentino Open, defeating Nuria Brancaccio in the final. In November, Oliynykova defeated Mayar Sherif in the final at the Tucumán Open to claim her second WTA 125 title. The following week, Oliynykova won the WTA 125 Copa LP Chile, overcoming Léolia Jeanjean in the final and moving into the top 100 at world No. 95 for the first time, on 24 November 2025.
Oliynykova made her Grand Slam debut at the 2026 Australian Open where she directly entered the main draw, but lost to defending champion Madison Keys.