2021 Open de Oeiras – Doubles

This was the first of four editions of the tournament in the 2021 ATP Challenger Tour calendar.

Mats Moraing and Oscar Otte won the title after defeating Riccardo Bonadio and Denis Yevseyev 6–1, 6–4 in the final.

Seeds
• # 🇫🇷 Enzo Couacaud / 🇫🇷 Manuel Guinard (quarterfinals)

• # 🇵🇪 Sergio Galdós / 🇪🇸 Sergio Martos Gornés (first round)

• # 🇲🇦 Elliot Benchetrit / 🇨🇿 Zdeněk Kolář (quarterfinals)

• # Gonçalo Falcão / Gonçalo Oliveira (quarterfinals)