# 2021 Western & Southern Open – Men's doubles

Pablo Carreño Busta and Alex de Minaur were the defending champions, but Carreño Busta chose not to defend his title and de Minaur played alongside Cameron Norrie instead. They lost in the quarterfinals to Marcel Granollers and Horacio Zeballos.
Granollers and Zeballos went on to win the title, defeating Steve Johnson and Austin Krajicek in the final, 7–6$^{(7–5)}$, 7–6$^{(7–5)}$.

## Seeds

The top four seeds received a bye into the second round.
* Nikola Mektić / Mate Pavić (second round)
* Marcel Granollers / Horacio Zeballos (champions)
* Juan Sebastián Cabal / Robert Farah (semifinals)
* Rajeev Ram / Joe Salisbury (quarterfinals)
* Kevin Krawietz / Horia Tecău (second round)
* John Peers / Filip Polášek (second round)
* Łukasz Kubot / Marcelo Melo (first round)
* Raven Klaasen / Ben McLachlan (first round)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| WC | Steve Johnson Austin Krajicek | 7$^7$ | 6$^8$ | [10] | | | | |
| 3 | Juan Sebastián Cabal Robert Farah | 6$^5$ | 7$^{10}$ | [3] | | | | |
| 3 | Juan Sebastián Cabal Robert Farah | 6$^5$ | 7$^{10}$ | [3] | WC | Steve Johnson Austin Krajicek | 6$^5$ | 6$^5$ |
| | | | | | 2 | Marcel Granollers Horacio Zeballos | 7$^7$ | 7$^7$ |
| Alt | Marcelo Arévalo Fabio Fognini | 3 | 4 | | 2 | Marcel Granollers Horacio Zeballos | 7$^7$ | 7$^7$ |
| 2 | Marcel Granollers Horacio Zeballos | 6 | 6 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| | | | | | 1 | N Mektić M Pavić | 7$^9$ | 5 | [5] | | | | | | | | | |
| | D Evans N Skupski | 3 | 6 | [3] | | H Hurkacz J Sinner | 6$^7$ | 7 | [10] | | | | | | | | | |
| | H Hurkacz J Sinner | 6 | 3 | [10] | | | | | | | H Hurkacz J Sinner | 3 | 1 | | | | | |
| WC | S Johnson A Krajicek | 7 | 7 | | | | | | | WC | S Johnson A Krajicek | 6 | 6 | | | | | |
| | F Auger-Aliassime M Daniell | 5 | 5 | | WC | S Johnson A Krajicek | 6 | 6 | | | | | | | | | | |
| | A Behar G Escobar | 4 | 6 | [10] | | A Behar G Escobar | 3 | 4 | | | | | | | | | | |
| 8 | R Klaasen B McLachlan | 6 | 3 | [8] | | | | | | | | | | WC | S Johnson A Krajicek | 7$^7$ | 6$^8$ | [10] |
| | | | | | | | | | | | | | | 3 | JS Cabal R Farah | 6$^5$ | 7$^{10}$ | [3] |
| | | | | | 3 | JS Cabal R Farah | 7$^7$ | 6 | | | | | | | | | | |
| | F Krajinović F Martin | 1 | 6 | [10] | | F Krajinović F Martin | 6$^3$ | 4 | | | | | | | | | | |
| | R Bopanna I Dodig | 6 | 4 | [7] | | | | | | 3 | JS Cabal R Farah | 6 | 6 | | | | | |
| | S Gillé J Vliegen | 4 | 6$^3$ | | | | | | | | T Pütz M Venus | 4 | 4 | | | | | |
| | W Koolhof J-L Struff | 6 | 7$^7$ | | | W Koolhof J-L Struff | 5 | 3 | | | | | | | | | | |
| | T Pütz M Venus | 6 | 6 | | | T Pütz M Venus | 7 | 6 | | | | | | | | | | |
| 7 | Ł Kubot M Melo | 2 | 3 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | K Krawietz H Tecău | 7 | 6 | | | | | | | | | | | | | | |
| | F Delbonis D Schwartzman | 5 | 3 | | 5 | K Krawietz H Tecău | 6 | 5 | [7] | | | | | | | | |
| Alt | M Arévalo F Fognini | 7 | 6$^5$ | [11] | Alt | M Arévalo F Fognini | 3 | 7 | [10] | | | | | | | | |
| Alt | A Karatsev D Lajović | 5 | 7$^7$ | [9] | | | | | | Alt | M Arévalo F Fognini | 6 | 7$^7$ | | | | |
| | A Golubev A Mies | 6$^5$ | 5 | | | | | | | 4 | R Ram J Salisbury | 4 | 6$^5$ | | | | |
| WC | N Monroe F Tiafoe | 7$^7$ | 7 | | WC | N Monroe F Tiafoe | 6$^{15}$ | 2 | | | | | | | | | |
| | | | | | 4 | R Ram J Salisbury | 7$^{17}$ | 6 | | | | | | | | | |
| | | | | | | | | | | | | | | Alt | M Arévalo F Fognini | 3 | 4 |
| 6 | J Peers F Polášek | 6$^4$ | 7$^7$ | [10] | | | | | | | | | | 2 | M Granollers H Zeballos | 6 | 6 |
| | M Middelkoop L Saville | 7$^7$ | 6$^2$ | [6] | 6 | J Peers F Polášek | 6 | 3 | [8] | | | | | | | | |
| | A Bublik C Garín | 2 | 2 | | | A de Minaur C Norrie | 3 | 6 | [10] | | | | | | | | |
| | A de Minaur C Norrie | 6 | 6 | | | | | | | | A de Minaur C Norrie | 3 | 4 | | | | |
| | S Bolelli M González | 7$^8$ | 3 | [9] | | | | | | 2 | M Granollers H Zeballos | 6 | 6 | | | | |
| | K Khachanov A Rublev | 6$^6$ | 6 | [11] | | K Khachanov A Rublev | 6$^7$ | 5 | | | | | | | | | |
| | | | | | 2 | M Granollers H Zeballos | 7$^9$ | 7 | | | | | | | | | |