2021 Open de Oeiras – Doubles
# 2021 Open de Oeiras – Doubles

This was the first of four editions of the tournament in the 2021 ATP Challenger Tour calendar.

Mats Moraing and Oscar Otte won the title after defeating Riccardo Bonadio and Denis Yevseyev 6–1, 6–4 in the final.

## Seeds

* Enzo Couacaud / Manuel Guinard (quarterfinals)
* Sergio Galdós / Sergio Martos Gornés (first round)
* Elliot Benchetrit / Zdeněk Kolář (quarterfinals)
* Gonçalo Falcão / Gonçalo Oliveira (quarterfinals)

## 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

| First round | First round | First round | First round | First round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final |
| - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1 | E Couacaud M Guinard | 6 | 6 | | | | | | | | | | | | | |
| WC | Pedro Araújo T Cação | 0 | 3 | | 1 | E Couacaud M Guinard | 3 | 6 | [5] | | | | | | | |
| Alt | H Bourchier K Uchida | 4 | 3 | | | T Gabashvili C-h Tseng | 6 | 2 | [10] | | | | | | | |
| | T Gabashvili C-h Tseng | 6 | 6 | | | | | | | T Gabashvili C-h Tseng | 2 | 3 | | | | |
| 3 | E Benchetrit Z Kolář | 6 | $7^7$ | | | | | | | R Bonadio D Yevseyev | 6 | 6 | | | | |
| WC | F Cabral Luís Faria | 3 | $6^5$ | | 3 | E Benchetrit Z Kolář | $7^7$ | 3 | [8] | | | | | | | |
| | H Johnson Y Johnson | 7 | 4 | [3] | | R Bonadio D Yevseyev | $6^3$ | 6 | [10] | | | | | | | |
| | R Bonadio D Yevseyev | 5 | 6 | [10] | | | | | | | | | | R Bonadio D Yevseyev | 1 | 4 |
| | A Collarini GM Moroni | 4 | 4 | | | | | | | | | | | M Moraing O Otte | 6 | 6 |
| | M Moraing O Otte | 6 | 6 | | | M Moraing O Otte | 6 | 6 | | | | | | | | |
| | E Escobedo V Orlov | 4 | 4 | | 4 | G Falcão G Oliveira | 3 | 2 | | | | | | | | |
| 4 | Gonçalo Falcão G Oliveira | 6 | 6 | | | | | | | M Moraing O Otte | 6 | 3 | [10] | | | |
| | L Miedler N Serdarušić | 6 | 6 | | | | | | | L Miedler N Serdarušić | 4 | 6 | [8] | | | |
| WC | Miguel Gomes H Rocha | 3 | 1 | | | L Miedler N Serdarušić | 6 | 6 | | | | | | | | |
| | P Kotov A Vatutin | 6 | 6 | | | P Kotov A Vatutin | 4 | 4 | | | | | | | | |
| 2 | S Galdós S Martos Gornés | 4 | 4 | | | | | | | | | | | | | |
