| 2021 Challenger Biel/Bienne | |
|---|---|
| Date | 20–26 September |
| Edition | 1st |
| Surface | Hard (Indoor) |
| Location | Biel/Bienne, Switzerland |
| Champions | |
| Singles | |
 Liam Broady | |
| Doubles | |
 Ruben Bemelmans /  Daniel Masur | |
The 2021 FlowBank Challenger Biel/Bienne was a professional tennis tournament played on indoor hard courts. It was the 1st edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Biel/Bienne, Switzerland between 20 and 26 September 2021.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 FRA | |||
 SUI | Henri Laaksonen | 119 | 2 |
 AUT | Dennis Novak | 121 | 3 |
 CZE | Tomáš Macháč | 143 | 4 |
| GBR | Liam Broady | 145 | 5 |
 POR | João Sousa | 150 | 6 |
| SUI | Marc-Andrea Hüsler | 160 | 7 |
 TUR | Cem İlkel | 176 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Liam Broady def. Marc-Andrea Hüsler 7–5, 6–3. Ruben Bemelmans / Daniel Masur def. Marc-Andrea Hüsler / Dominic Stricker Walkover.
