2021 Zavarovalnica Sava Portorož – Singles

Anna Chakvetadze was the champion when the event was last held in 2010, but she retired from professional tennis in 2013.

Jasmine Paolini won her maiden WTA Tour title, defeating Alison Riske in the final, 7–6(7–4), 6–2.

Seeds
• # Petra Martić (first round)

• # 🇰🇿 Yulia Putintseva (semifinals)

• # 🇺🇸 Alison Riske (final)

• # 🇷🇴 Sorana Cîrstea (quarterfinals)

• # Tamara Zidanšek (quarterfinals)

• # 🇺🇦 Dayana Yastremska (first round, retired)

• # 🇸🇪 Rebecca Peterson (first round)

• # Donna Vekić (first round)

Seeds
• # Lesley Pattinama Kerkhove (first round)

• # 🇸🇰 Viktória Kužmová (qualified)

• # 🇺🇸 Grace Min (first round, retired)

• # 🇮🇹 Lucia Bronzetti (qualified)

• # 🇷🇸 Aleksandra Krunić (qualified)

• # 🇬🇧 Katie Boulter (qualified)

• # 🇮🇹 Lucrezia Stefanini (qualifying competition)

• # 🇵🇱 Urszula Radwańska (first round, retired)

• # Susan Bandecchi (qualifying competition)

• # Tereza Mrdeža (qualified)

• # 🇧🇾 Yuliya Hatouka (qualifying competition)

• # 🇷🇴 Irina Fetecău (qualifying competition)

Qualifiers
• # 🇮🇹 Cristiana Ferrando

• # 🇸🇰 Viktória Kužmová

• # Tereza Mrdeža

• # 🇮🇹 Lucia Bronzetti

• # 🇷🇸 Aleksandra Krunić

• # 🇬🇧 Katie Boulter