Teodora Kostović (Serbian Cyrillic: Теодора Костовић; born 28 June 2007) is a Serbian professional tennis player. She reached her best WTA singles ranking of world No. 146 on 27 July 2026.
Early life and background
Kostović comes from a sports-focused family and has a brother named Miloš. She began playing tennis at age five and reportedly expressed an early ambition to become the world No. 1 ranked player.
Career
Junior events
Competing on the ITF Junior Circuit, Kostović achieved a career-high ranking of world No. 6.
She won J300 singles titles on clay courts in Plovdiv and Vrsar in 2023.
In 2024, she claimed five J300 titles across all three major surfaces. Her victories included wins on grass in Roehampton, on hard courts in College Park, and on clay in Bradenton, Oberpullendorf, and Bytom. That same year, she was also a finalist at the J500 event on clay in Offenbach, and the J300 event on hard courts in Indian Wells.
Aged 16, Kostović made her professional debut on the ITF Women's World Tennis Tour in Kuršumlijska Banja, Serbia. In May 2024, she reached the singles semifinals of a W15 event there, losing in three sets to compatriot Anja Stanković. Later in 2024, she played four additional tournaments in the same town at the W15 and W75 levels, not advancing past the quarterfinals in any of them.
2025: WTA debut
Kostović made her WTA Tour singles debut in February at the WTA 500Abu Dhabi Open, entering the qualifying draw via a wildcard earned through a junior tournament result. In the first qualifying round, she won the first set 6–2 against Diane Parry before the French player retired from the match. In the final qualifying round, Kostović initially led 4–1 against McCartney Kessler but ultimately lost 4–6, 2–6.
The following month, she received a wildcard into the qualifying rounds of the WTA 1000Miami Open. Ranked No. 756 at the time, Kostović defeated world No. 99 and 17th qualifying seed Olivia Gadecki in the first round. She lost to Greet Minnen in the final qualifying round.
In April, Kostović received a wildcard for the qualifying rounds and subsequently qualified for the main draw of the WTA 1000 in Madrid. She achieved this by defeating top-100 player Elena-Gabriela Ruse in the first qualifying round and then Lucrezia Stefanini in the final qualifying round. Entering the main draw of Madrid, Kostović, ranked No. 625, was the lowest-ranked participant aside from those using a protected ranking. She was also the youngest player in the main draw. In the first round, she lost to Eva Lys in straight sets.
Kostović received her first nomination to represent Serbia in the Billie Jean King Cup in April 2025, under the captaincy of Dušan Vemić, for the 2025 Billie Jean King Cup Europe/Africa Zone Group I event against Slovenia and Lithuania, and later in the promotional play-off tie against Croatia. She made her debut for the national team on 10 April 2025, recording a victory over Klaudija Bubelytė of Lithuania.
Performance timelines
Key
W
F
SF
QF
#R
RR
Q#
P#
DNQ
A
Z#
PO
G
S
B
NMS
NTI
P
NH
(W) winner; (F) finalist; (SF) semifinalist; (QF) quarterfinalist; (#R) rounds 4, 3, 2, 1; (RR) round-robin stage; (Q#) qualification round; (P#) preliminary round; (DNQ) did not qualify; (A) absent; (Z#) Davis/Fed Cup Zonal Group (with number indication) or (PO) play-off; (G) gold, (S) silver or (B) bronze Olympic/Paralympic medal; (NMS) not a Masters tournament; (NTI) not a Tier I tournament; (P) postponed; (NH) not held; (SR) strike rate (events won / competed); (W–L) win–loss record.
To avoid confusion and double counting, these charts are updated at the conclusion of a tournament or when the player's participation has ended.
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Serbia
