2021 Croatia Open Umag – Doubles

Robin Haase and Philipp Oswald were the reigning champions from when the tournament was last held in 2019, but chose not to defend their title.

Fernando Romboli and David Vega Hernández won the title, defeating Tomislav Brkić and Nikola Ćaćić in the final, 6–3, 7–5.

Seeds
• # 🇧🇦 Tomislav Brkić / 🇷🇸 Nikola Ćaćić (final)

• # Pablo Cuevas / 🇫🇷 Fabrice Martin (first round)

• # 🇧🇷 Rafael Matos / 🇧🇾 Andrei Vasilevski (first round)

• # 🇻🇪 Luis David Martínez / 🇳🇿 Artem Sitak (first round)