2021 Bol Open – Singles

Tamara Zidanšek was the two-time defending champion, having won the last edition in 2019, however she was unable to defend her title as she was still competing at the 2021 French Open, reaching the semi-final of the Grand Slam.

Jasmine Paolini won the title, defeating Arantxa Rus in the final, 6–2, 7–6(7–4).

Seeds
• # 🇷🇺 Anna Blinkova (semifinals)

• # Arantxa Rus (final)

• # 🇮🇹 Jasmine Paolini (champion)

• # 🇮🇹 Martina Trevisan (quarterfinals)

• # 🇮🇹 Sara Errani (second round)

• # 🇷🇺 Liudmila Samsonova (second round)

• # 🇪🇸 Aliona Bolsova (first round)

• # 🇭🇺 Tímea Babos (first round)

Seeds
• # 🇪🇸 Lara Arruabarrena (qualifying competition)

• # 🇺🇸 Asia Muhammad (qualifying competition)

• # 🇺🇸 Whitney Osuigwe (qualifying competition)

• # Ekaterine Gorgodze (qualified)

Qualifiers
• # 🇷🇴 Alexandra Cadanțu

• # 🇭🇺 Dalma Gálfi

• # Lulu Sun

• # Ekaterine Gorgodze