| Doubles | |
|---|---|
| 2021 Moselle Open | |
| Champions |  Hubert Hurkacz Jan Zieliński |
| Runners-up |  Hugo Nys  Arthur Rinderknech |
| Final score | 7–5, 6–3 |
Robert Lindstedt and Jan-Lennard Struff were the defending champions, having won the previous edition in 2019, [1] but chose not to defend their title.
Hubert Hurkacz and Jan Zieliński won the title, defeating Hugo Nys and Arthur Rinderknech in the final, 7–5, 6–3.
Henri Kontinen / 
Ben McLachlan (Semifinals)
Tomislav Brkić / 
Nikola Ćaćić (Semifinals)
Oliver Marach / Philipp Oswald (Quarterfinals)
Luke Saville / John-Patrick Smith (First round)| First Round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | H Kontinen B McLachlan | 77 | 7 | ||||||||||||||||||||||||
M Reid  K Skupski | 63 | 5 | 1 | H Kontinen B McLachlan | 1 | 7 | [10] | ||||||||||||||||||||
A de Minaur  D Vega Hernández | 3 | 6 | [5] | WC | G Barrère L Pouille | 6 | 5 | [7] | |||||||||||||||||||
| WC | G Barrère L Pouille | 6 | 3 | [10] | 1 | H Kontinen B McLachlan | 4 | 4 | |||||||||||||||||||
| 3 | O Marach P Oswald | 6 | 6 | H Hurkacz J Zieliński | 6 | 6 | |||||||||||||||||||||
N Mahut  V Pospisil | 4 | 3 | 3 | O Marach P Oswald | 3 | 4 | |||||||||||||||||||||
| H Hurkacz J Zieliński | 6 | 6 | H Hurkacz J Zieliński | 6 | 6 | ||||||||||||||||||||||
S Walków  I Zelenay | 3 | 3 | H Hurkacz J Zieliński | 7 | 6 | ||||||||||||||||||||||
 I Sabanov M Sabanov | 3 | 6 | [10] | H Nys A Rinderknech | 5 | 3 | |||||||||||||||||||||
| WC | D Added U Humbert | 6 | 3 | [8] | I Sabanov M Sabanov | 3 | 4 | ||||||||||||||||||||
| H Nys A Rinderknech | 6 | 7 | H Nys A Rinderknech | 6 | 6 | ||||||||||||||||||||||
| 4 | L Saville J-P Smith | 3 | 5 | H Nys A Rinderknech | 6 | 77 | |||||||||||||||||||||
| Alt |  H Reese  S Verbeek | 6 | 3 | [10] | 2 | T Brkić N Ćaćić | 3 | 63 | |||||||||||||||||||
J O'Mara  D Sharan | 3 | 6 | [8] | Alt | H Reese S Verbeek | 3 | 3 | ||||||||||||||||||||
| M Giron A Olivetti | 4 | 77 | [1] | 2 | T Brkić N Ćaćić | 6 | 6 | ||||||||||||||||||||
| 2 | T Brkić N Ćaćić | 6 | 63 | [10] | |||||||||||||||||||||||
Jordan Kerr and Robert Lindstedt were the defending champions, but lost in the semifinals to Mikhail Youzhny and Mischa Zverev.
Jeff Coetzee and Wesley Moodie were the defending champions, but Coetzee chose not to participate that year.
Moodie partnered with Dick Norman, but lost in the semifinals to Martin Damm and Robert Lindstedt.
Wesley Moodie and Dick Norman were defending champions, but they lost in the semifinals against Robert Lindstedt and Horia Tecău.
Lindstedt and Tecău won the final 1–6, 7–5, [10–7] against Lukáš Dlouhý and Leander Paes.
Michaël Llodra and Nenad Zimonjić were the defending champions but decided not to participate together.
Llodra was scheduled to play alongside Juan Martín del Potro but withdrew from the first round while Zimonjić partnered up with Robert Lindstedt and successfully defended the title, defeating Thiemo de Bakker and Jesse Huta Galung in the final 5–7, 6–3, [10–8].
Robert Lindstedt and Horia Tecău were the defending champions, but Lindstedt decided to participate in Barcelona instead.
Tecău successfully defended the title alongside Max Mirnyi, defeating Lukáš Dlouhý and Oliver Marach in the final, 4–6, 6–4, [10–6].
Robert Lindstedt and Horia Tecău were the defending champions but Lindstedt decided not to participate.
Tecău plays alongside Max Mirnyi and won the title beating in the final Andre Begemann and Martin Emmrich, 6–3, 7–6(7–4).
Robert Lindstedt and Horia Tecău were the defending champions, but decided not to participate together. Lindstedt played alongside Daniel Nestor, while Tecǎu teams up with Max Mirnyi. Each team lose in the second round.
Johan Brunström and Nicholas Monroe were the defending champions, but chose not to participate together. Brunström played alongside Robert Lindstedt, but lost in the quarterfinals to Thomaz Bellucci and João Souza. Monroe teamed up with Artem Sitak, but lost in the semifinals to Juan Sebastián Cabal and Robert Farah.
Jérémy Chardy and Łukasz Kubot won the title, defeating Cabal and Farah in the final, 6–7(6–8), 6–3, [10–8].
Marin Draganja and Florin Mergea were the defending champions, but Mergea decided not to participate this year. Draganja paired up with Henri Kontinen, but lost in the first round to Martin Kližan and Lukáš Rosol.
Jamie Murray and John Peers won the title, defeating Juan Sebastián Cabal and Robert Farah in the final, 2–6, 6–3, [10–8].
Andy Murray was the defending champion, but chose not to participate.
David Ferrer won the title, defeating Steve Johnson in the final, 4–6, 6–4, 7–5.
Radu Albot and Dušan Lajović were the defending champions, but Lajović chose not to participate this year. Albot played alongside Illya Marchenko, but lost in the first round to Dominic Inglot and Robert Lindstedt.
Flavio Cipolla and Dudi Sela won the title, defeating Andrés Molteni and Diego Schwartzman in the final, 6–3, 5–7, [10–7].
Dominic Inglot and Robert Lindstedt were the defending champions, but chose not to participate together. Inglot played alongside Marin Draganja, but lost in the quarterfinals to Lindstedt and Aisam-ul-Haq Qureshi. Lindstedt and Qureshi then lost in the semifinals to Andre Begemann and Leander Paes.
David Ferrer was the defending champion, but withdrew from his semifinal match against Andy Murray.
Jean-Julien Rojer and Horia Tecău were the defending champions, and successfully defended their title, defeating James Cerretani and Leander Paes in the final, 6–2, 7–6(7–2).
Jamie Murray and Bruno Soares were defending champions, but chose not to defend their title.
Oliver Marach and Mate Pavić were the defending champions, but lost to Ben McLachlan and Jan-Lennard Struff in the semifinals.
Henri Kontinen and John Peers were the defending champions, but lost in the semifinals to Feliciano López and Andy Murray.
Nikoloz Basilashvili was the defending champion and successfully defended his title, defeating Andrey Rublev in the final, 7–5, 4–6, 6–3. En route to doing so, Basilashvili saved two match points against Alexander Zverev in the semifinals.
Nicolas Mahut and Édouard Roger-Vasselin were the defending champions, but lost in the final to Robert Lindstedt and Jan-Lennard Struff, 6–2, 6–7(1–7), [4–10].
Ben McLachlan and Jan-Lennard Struff were the defending champions, but Struff chose not to participate.
| Grand Slam events | |
|---|---|
| ATP Tour Masters 1000 | |
| ATP Tour 500 | |
| ATP Tour 250 |
|
| Team events | |
 – Tournaments are affected by the COVID-19 pandemic * – Tournaments are introduced due to the impact of the COVID-19 pandemic | |