2021 Belgrade Challenger – Men's doubles

This was the first of the three tournaments held in Belgrade for the 2021 tennis season. Belgrade also hosted a joint ATP/WTA tournament.

Guillermo Durán and Andrés Molteni won the title after defeating Tomislav Brkić and Nikola Ćaćić 6–4, 6–4 in the final.

Seeds
• # 🇲🇽 Santiago González / 🇮🇳 Divij Sharan (first round)

• # 🇬🇧 Luke Bambridge / 🇬🇧 Dominic Inglot (first round)

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

• # 🇺🇸 Nicholas Monroe / 🇦🇺 John-Patrick Smith (first round)