2021 J&T Banka Ostrava Open – Doubles
# 2021 J&T Banka Ostrava Open – Doubles

Elise Mertens and Aryna Sabalenka were the defending champions, but chose not to participate.

Sania Mirza and Zhang Shuai won the title, defeating Kaitlyn Christian and Erin Routliffe in the final, 6–3, 6–2.

## Seeds

* Magda Linette / Bernarda Pera (semifinals, withdrew)
* Sania Mirza / Zhang Shuai (champions)
* Kaitlyn Christian / Erin Routliffe (final)
* Eri Hozumi / Makoto Ninomiya (semifinals)

## 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

### Draw

| First round | First round | First round | First round | First round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1 | M Linette B Pera | 6 | 6 | | | | | | | | | | | | | | |
| | A Mitu A Rosolska | 0 | 4 | | 1 | M Linette B Pera | 6 | 6 | | | | | | | | | |
| | A Sharma R van der Hoek | 7 | 7 | | | A Sharma R van der Hoek | 4 | 2 | | | | | | | | | |
| | A Fomina-Klotz K Kawa | 5 | 5 | | | | | | | 1 | M Linette B Pera | | | | | | |
| 3 | K Christian E Routliffe | 6 | 6 | | | | | | | 3 | K Christian E Routliffe | w/o | | | | | |
| Alt | R Bhosale E Webley-Smith | 3 | 4 | | 3 | K Christian E Routliffe | 6 | 6 | | | | | | | | | |
| | A Blinkova M Doi | 6 | 2 | [13] | | V Heisen R Voráčová | 3 | 2 | | | | | | | | | |
| | V Heisen R Voráčová | 1 | 6 | [15] | | | | | | | | | | 3 | K Christian E Routliffe | 3 | 2 |
| | O Kalashnikova M Kato | 6 | 6 | | | | | | | | | | | 2 | S Mirza S Zhang | 6 | 6 |
| | J Lohoff A Panova | 1 | 2 | | | O Kalashnikova M Kato | 4 | 2 | | | | | | | | | |
| | K Piter K Zimmermann | 3 | 6 | [6] | 4 | E Hozumi M Ninomiya | 6 | 6 | | | | | | | | | |
| 4 | E Hozumi M Ninomiya | 6 | 3 | [10] | | | | | | 4 | E Hozumi M Ninomiya | 2 | 5 | | | | |
| | N Dzalamidze Y Sizikova | 3 | $7^7$ | [6] | | | | | | 2 | S Mirza S Zhang | 6 | 7 | | | | |
| | A Danilina L Marozava | 6 | $6^3$ | [10] | | A Danilina L Marozava | 3 | 6 | [6] | | | | | | | | |
| | E Bektas T Moore | $7^7$ | 5 | [7] | 2 | S Mirza S Zhang | 6 | 3 | [10] | | | | | | | | |
| 2 | S Mirza S Zhang | $6^3$ | 7 | [10] | | | | | | | | | | | | | |
