This was the first edition of the tournament.[1]
| Doubles | |
|---|---|
| 2021 Bucharest Challenger | |
| Champions |  Ruben Gonzales Hunter Johnson |
| Runners-up |  Maximilian Marterer Lukáš Rosol |
| Score | 1–6, 6–2, [10–3] |
Ruben Gonzales and Hunter Johnson won the title after defeating Maximilian Marterer and Lukáš Rosol 1–6, 6–2, [10–3] in the final.
Seeds edit
James Cerretani / 
Luca Margaroli (semifinals)
Alexander Erler / Lucas Miedler (quarterfinals)
Ruben Gonzales / Hunter Johnson (champions)
Vitaliy Sachko / 
Nino Serdarušić (withdrew)
Draw edit
Key edit
- 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 | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | J Cerretani L Margaroli
| 7 | 6 | ||||||||||||||||||||||||
 T Gabashvili G Smits
| 5 | 2 | 1 | J Cerretani L Margaroli
| 6 | 710 | |||||||||||||||||||||
 F Cobolli J Ocleppo
| 79 | 6 | F Cobolli J Ocleppo
| 4 | 68 | ||||||||||||||||||||||
| WC |  M Copil A Ungur
| 67 | 1 | 1 | J Cerretani L Margaroli
| 3 | 6 | [3] | |||||||||||||||||||
| Alt |  U Ignatik DN Mădăraș
| 5 | 7 | [10] | M Marterer L Rosol
| 6 | 3 | [10] | |||||||||||||||||||
| V Kopřiva J Lehečka
| 7 | 5 | [4] | Alt | U Ignatik DN Mădăraș
| 64 | 3 | ||||||||||||||||||||
| M Marterer L Rosol
| 6 | 6 | M Marterer L Rosol
| 77 | 6 | ||||||||||||||||||||||
| Alt |  G Blancaneaux V Orlov
| 3 | 3 | M Marterer L Rosol
| 6 | 2 | [3] | ||||||||||||||||||||
 R Albot A Cozbinov
| 77 | 4 | [10] | 3 | R Gonzales H Johnson
| 1 | 6 | [10] | |||||||||||||||||||
 J Clarke J Sels
| 64 | 6 | [4] | R Albot A Cozbinov
| 3 | 77 | [6] | ||||||||||||||||||||
| WC | ND Ionel FC Jianu
| 1 | 5 | 3 | R Gonzales H Johnson
| 6 | 62 | [10] | |||||||||||||||||||
| 3 | R Gonzales H Johnson
| 6 | 7 | 3 | R Gonzales H Johnson
| 6 | 77 | ||||||||||||||||||||
| PR | A Motti A Vatutin
| 6 | 63 | [3] | WC | A Jecan DA Tomescu
| 4 | 64 | |||||||||||||||||||
| WC | A Jecan Dan Alexandru Tomescu
| 4 | 77 | [10] | WC | A Jecan DA Tomescu
| 0 | 6 | [11] | ||||||||||||||||||
| R Bonadio S Travaglia
| 3 | 3 | 2 |  A Erler L Miedler
| 6 | 4 | [9] | ||||||||||||||||||||
| 2 | A Erler L Miedler
| 6 | 6 | ||||||||||||||||||||||||