| Men's doubles | |
|---|---|
| 2021 Belgrade Challenger | |
| Champions |  Guillermo Durán Andrés Molteni |
| Runners-up |  Tomislav Brkić  Nikola Ćaćić |
| Final score | 6–4, 6–4 |
This was the first of the three tournaments held in Belgrade for the 2021 tennis season. Belgrade also hosted a joint ATP/WTA tournament. [1]
Guillermo Durán and Andrés Molteni won the title after defeating Tomislav Brkić and Nikola Ćaćić 6–4, 6–4 in the final.
Santiago González / 
Divij Sharan (first round)
Luke Bambridge / Dominic Inglot (first round) Tomislav Brkić / Nikola Ćaćić (final)
Nicholas Monroe / 
John-Patrick Smith (first round)| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | S González D Sharan | 3 | 3 | ||||||||||||||||||||||||
 J Erlich  A Vasilevski | 6 | 6 | J Erlich A Vasilevski | 6 | 6 | ||||||||||||||||||||||
L Glasspool  H Heliövaara | 6 | 4 | [5] |  A Sitak  D Vega Hernández | 1 | 1 | |||||||||||||||||||||
| A Sitak D Vega Hernández | 2 | 6 | [10] | J Erlich A Vasilevski | 6 | 5 | [9] | ||||||||||||||||||||
| 4 | N Monroe J-P Smith | 7 | 4 | [0] | G Durán A Molteni | 3 | 7 | [11] | |||||||||||||||||||
| G Durán A Molteni | 5 | 6 | [10] | G Durán A Molteni | 6 | 6 | |||||||||||||||||||||
 A Begemann  A Vavassori | 7 | 6 | A Begemann A Vavassori | 2 | 4 | ||||||||||||||||||||||
| N Lammons J Withrow | 5 | 3 | G Durán A Molteni | 6 | 6 | ||||||||||||||||||||||
| WC | H Međedović M Topo | 5 | 63 | 3 | T Brkić N Ćaćić | 4 | 4 | ||||||||||||||||||||
 R Jebavý  I Zelenay | 7 | 77 | R Jebavý I Zelenay | 66 | 3 | ||||||||||||||||||||||
| WC | V Troicki M Zekić | 4 | 2 | 3 | T Brkić N Ćaćić | 78 | 6 | ||||||||||||||||||||
| 3 | T Brkić N Ćaćić | 6 | 6 | 3 | T Brkić N Ćaćić | 6 | 78 | ||||||||||||||||||||
| WC | M Miladinović M Tepavac | 3 | 2 | F Bagnis F Cerúndolo | 0 | 66 | |||||||||||||||||||||
 A Göransson J O'Mara | 6 | 6 | A Göransson J O'Mara | 3 | 3 | ||||||||||||||||||||||
| F Bagnis F Cerúndolo | 4 | 711 | [11] | F Bagnis F Cerúndolo | 6 | 6 | |||||||||||||||||||||
| 2 | L Bambridge D Inglot | 6 | 69 | [9] | |||||||||||||||||||||||
Nikola Ćaćić is a Serbian professional tennis player. He has a career-high ranking of World No. 35 in doubles achieved on 8 November 2021. He has won three doubles titles in the ATP Tour, four doubles titles in the ATP Challenger Tour, as well as five singles and 32 doubles titles in ITF Futures tournaments.
Mateusz Kowalczyk and Andreas Mies were the defending champions but chose not to defend their title.
This was the first edition of the tournament.
Attila Balázs and Gonçalo Oliveira were the defending champions but chose not to defend their title.
Jurij Rodionov and Emil Ruusuvuori were the defending champions but chose not to defend their title.
Denys Molchanov and Igor Zelenay were the defending champions but chose not to defend their title.
Filippo Baldi and Andrea Pellegrino were the defending champions but chose not to defend their title.
Sander Gillé and Joran Vliegen were the defending champions but chose not to defend their title.
This was the first edition of the tournament.
Marcelo Demoliner and Matwé Middelkoop were the defending champions, but Middelkoop decide to participate in the 2021 Open Sud de France instead. Demoliner was pairing up with Santiago González, but they lost in the first round to Guillermo Durán and Andrés Molteni.
Marcel Granollers and Horacio Zeballos were the defending champions, but they decided not to participate this year.
This was the first edition of the tournament, primarily organised due to the cancellation of some tournaments in 2021, due to the COVID-19 pandemic.
Oliver Marach and Mate Pavić were the two-time defending champions from when the event was last held in 2019 but lost in the first round to Tomislav Brkić and Nikola Ćaćić.
John Peers and Michael Venus were the defending champions, but Peers chose not to participate this year.
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.
Robert Lindstedt and Jan-Lennard Struff were the reigning champions from when the tournament was last held in 2019, but chose not to participate this year.
Jamie Murray and Neal Skupski were the defending champions, but chose to compete in San Diego with different partners instead.
Marcelo Demoliner and Matwé Middelkoop were the reigning champions from when the tournament was last held in 2019, but chose to compete with different partners. Demoliner played alongside Marcus Daniell, but lost in the first round to Ariel Behar and Gonzalo Escobar.
Wesley Koolhof and Neal Skupski defeated Ariel Behar and Gonzalo Escobar in the final, 7–6(7–5), 6–4, to win the men's doubles tennis title at the 2022 Adelaide International 2.
Tomislav Brkić and Nikola Ćaćić were the defending champions but lost in the semifinals to Santiago González and Andrés Molteni.