2021 Lošinj Open – Doubles
# 2021 Lošinj Open – Doubles

This was the first edition of the tournament.

Andrej Martin and Tristan-Samuel Weissborn won the title after defeating Victor Vlad Cornea and Ergi Kırkın 6–1, $7–6^{(7–5)}$ in the final.

## Seeds

* Sadio Doumbia / Fabien Reboul (quarterfinals)
* Antonio Šančić / Artem Sitak (semifinals)
* Marco Bortolotti / Sergio Martos Gornés (first round)
* James Cerretani / Fabian Fallert (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

| First round | First round | First round | First round | First round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final |
| - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1 | S Doumbia F Reboul | 7 | 6 | | | | | | | | | | | | | | |
| | J Forejtek FC Jianu | 5 | 4 | | 1 | S Doumbia F Reboul | 2 | 3 | | | | | | | | | |
| | J Barranco Cosano Á López San Martín | 3 | 5 | | | A Martin T-S Weissborn | 6 | 6 | | | | | | | | | |
| | A Martin T-S Weissborn | 6 | 7 | | | | | | | | A Martin T-S Weissborn | 6 | 6 | | | | |
| 4 | J Cerretani F Fallert | 3 | $7^7$ | [10] | | | | | | 4 | J Cerretani F Fallert | 3 | 4 | | | | |
| | D Petrović I Sabanov | 6 | $6^5$ | [3] | 4 | J Cerretani F Fallert | 7 | 6 | | | | | | | | | |
| WC | A Kalender M Poljičak | 2 | $7^7$ | [5] | WC | A Chandrasekar VS Prashanth | 5 | 3 | | | | | | | | | |
| WC | A Chandrasekar VS Prashanth | 6 | $6^3$ | [10] | | | | | | | | | | | A Martin T-S Weissborn | 6 | $7^7$ |
| | N Fatić A Šetkić | 1 | 2 | | | | | | | | | | | | VV Cornea E Kırkın | 1 | $6^5$ |
| | VV Cornea E Kırkın | 6 | 6 | | | VV Cornea E Kırkın | 6 | 1 | [10] | | | | | | | | |
| | G Blancaneaux A Kadhe | 6 | 7 | | | G Blancaneaux A Kadhe | 3 | 6 | [4] | | | | | | | | |
| 3 | M Bortolotti S Martos Gornés | 2 | 5 | | | | | | | | VV Cornea E Kırkın | 0 | 6 | [10] | | | |
| | R Haase Mats Hermans | 6 | 6 | | | | | | | 2 | A Šančić A Sitak | 6 | 0 | [5] | | | |
| WC | Anthony Genov Eldin Nokic | 4 | 4 | | | R Haase M Hermans | 5 | 4 | | | | | | | | | |
| | N Álvarez Varona Georgii Kravchenko | $6^3$ | 1 | | 2 | A Šančić A Sitak | 7 | 6 | | | | | | | | | |
| 2 | A Šančić A Sitak | $7^7$ | 6 | | | | | | | | | | | | | | |
