2021 Winners Open
The 2021 WTA Romanian Open, known as the Winners Open due to sponsorship reasons, was a professional women's tennis tournament played on outdoor clay courts at the Winners Sports Club. It was the 1st edition of the tournament held in the city of Cluj-Napoca and was a part of the 2021 WTA Tour.
Finals
Singles
- Andrea Petkovic def. Mayar Sherif, 6–1, 6–1.
Doubles
- Natela Dzalamidze / Kaja Juvan def. Katarzyna Piter / Mayar Sherif, 6–3, 6–4.
Singles main-draw entrants
Seeds
- Rankings are as of July 26, 2021.
Other entrants
The following player received entry using a protected ranking:
- Andrea Petkovic
- Alexandra Dulgheru
- Jana Fett
- Aleksandra Krunić
- Seone Mendez
- Paula Ormaechea
- Panna Udvardy
Withdrawals
- Tímea Babos → replaced by Katarzyna Kawa
- Irina-Camelia Begu → replaced by Viktória Kužmová
- Elisabetta Cocciaretto → replaced by Mihaela Buzărnescu
- Zarina Diyas → replaced by Jaqueline Cristian
- Sara Errani → replaced by Kristína Kučová
- Viktorija Golubic → replaced by Mayar Sherif
- Polona Hercog → replaced by Anna Karolína Schmiedlová
- Tereza Martincová → replaced by Lesia Tsurenko
- Jasmine Paolini → replaced by Réka Luca Jani
- Arantxa Rus → replaced by Çağla Büyükakçay
- Patricia Maria Țig → replaced by Lara Arruabarrena
Doubles main-draw entrants
Seeds
- Rankings are as of July 26, 2021.
Other entrants
- Ana Bogdan / Jaqueline Cristian
- Miriam Bulgaru / Irina Fetecău
- Alexandra Panova / Julia Wachaczyk
Withdrawals
- Irina-Camelia Begu / Andreea Mitu → replaced by Lara Arruabarrena / Andreea Mitu
- Anna Bondár / Fanny Stollár → replaced by Katarzyna Piter / Mayar Sherif
- Anna Danilina / Ulrikke Eikeri → replaced by Anna Bondár / Ulrikke Eikeri
- Viktória Kužmová / Arantxa Rus → replaced by Alena Fomina / Ekaterina Yashina
- Vivian Heisen / Alicja Rosolska → replaced by Viktória Kužmová / Alicja Rosolska
- Ekaterine Gorgodze / Paula Kania-Choduń → replaced by Oana Georgeta Simion / Gabriela Talabă