2021 İstanbul Cup
The 2021 İstanbul Cup is a tennis tournament played on outdoor clay courts. It is the 14th edition of the İstanbul Cup, and part of the WTA International tournaments of the 2021 WTA Tour. It took place in Istanbul, Turkey, from 19 through 25 April 2021.
Finals
Singles
- Sorana Cîrstea defeated Elise Mertens, 6–1, 7–6
Doubles
- Veronika Kudermetova / Elise Mertens defeated Nao Hibino / Makoto Ninomiya, 6–1, 6–1
Singles main-draw entrants
Seeds
Other entrants
The following players received wildcardThe following players received entry from the qualifying draw:
- Lara Arruabarrena
- Cristina Bucșa
- Anastasia Gasanova
- Tereza Mrdeža
- Nuria Párrizas Díaz
- Kamilla Rakhimova
Withdrawals
;Before the tournament- Alizé Cornet → replaced by Zarina Diyas
- Svetlana Kuznetsova → replaced by Kateřina Siniaková
- Magda Linette → replaced by Nao Hibino
- Yulia Putintseva → replaced by Sara Errani
- Anastasija Sevastova → replaced by Marta Kostyuk
- Sara Sorribes Tormo → replaced by Anastasia Potapova
- Jil Teichmann → replaced by Viktorija Golubic
- Patricia Maria Țig → replaced by Ana Bogdan
- Zheng Saisai → replaced by Barbara Haas
Retirements
Doubles main-draw entrants
Seeds
1 Rankings as of April 12, 2021.Other entrants
The following pairs received wildcardThe following pairs received entry using protected rankings:
Withdrawals
;Before the tournament- Arantxa Rus / Tamara Zidanšek → replaced by Beatrice Gumulya / Jessy Rompies