2021 Hamburg European Open – Men's doubles

John Peers and Michael Venus were the defending champions, but Peers chose not to participate this year.

Venus played alongside Tim Pütz and successfully defended his title, defeating Kevin Krawietz and Horia Tecău in the final, 6–3, 6–7(3–7), [10–8].

Seeds
• # 🇩🇪 Kevin Krawietz / 🇷🇴 Horia Tecău (final)

• # 🇩🇪 Tim Pütz / 🇳🇿 Michael Venus (champions)

• # Matwé Middelkoop / Hugo Nys (first round)

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

Seeds
• # Ruben Gonzales / 🇺🇸 Hunter Johnson (qualifying competition; Lucky losers)

• # 🇮🇹 Alessandro Giannessi / 🇪🇸 Carlos Taberner (qualified)

Qualifiers

 * 1) 🇮🇹 Alessandro Giannessi / 🇪🇸 Carlos Taberner

Lucky losers

 * 1)  Ruben Gonzales / 🇺🇸 Hunter Johnson