# 2021 Biella Challenger VI – Singles

Juan Pablo Varillas was the defending champion but chose not to defend his title.
Thanasi Kokkinakis won the title after defeating Enzo Couacaud 6–3, 6–4 in the final.

## Seeds

* Paolo Lorenzi (first round)
* Zhang Zhizhen (semifinals)
* Enzo Couacaud (final)
* Alexandre Müller (quarterfinals)
* Dmitry Popko (first round)
* Alex Bolt (first round)
* João Menezes (first round)
* Bjorn Fratangelo (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

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| Q | Tomás Martín Etcheverry | 1 | 7 | 4 | | | | |
| 3 | Enzo Couacaud | 6 | 5 | 6 | | | | |
| 3 | Enzo Couacaud | 6 | 5 | 6 | 3 | Enzo Couacaud | 3 | 4 |
| | | | | | | Thanasi Kokkinakis | 6 | 6 |
| | Thanasi Kokkinakis | 6 | 4 | 6 | | Thanasi Kokkinakis | 6 | 6 |
| 2 | Zhang Zhizhen | 2 | 6 | 3 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1/WC | P Lorenzi | 0 | 6$^5$ | | | | | | | | | | | | | | | | |
| Q | TM Etcheverry | 6 | 7$^7$ | | Q | TM Etcheverry | 4 | 7$^7$ | 4 | | | | | | | | | | |
| | F Meligeni Alves | 6 | 6 | | | F Meligeni Alves | 6 | 6$^0$ | 0$^r$ | | | | | | | | | | |
| | J Clarke | 3 | 3 | | | | | | | Q | TM Etcheverry | 6 | 6 | | | | | | |
| | T Lamasine | 5 | 6 | 1 | | | | | | | F Mena | 3 | 2 | | | | | | |
| | D Kuzmanov | 7 | 4 | 6 | | D Kuzmanov | 2 | 7$^8$ | 1 | | | | | | | | | | |
| | F Mena | 6 | 6 | | | F Mena | 6 | 6$^6$ | 6 | | | | | | | | | | |
| 7 | J Menezes | 3 | 4 | | | | | | | | | | | | Q | TM Etcheverry | 1 | 7 | 4 |
| 3 | E Couacaud | 6 | 6 | | | | | | | | | | | | 3 | E Couacaud | 6 | 5 | 6 |
| | T Kamke | 4 | 2 | | 3 | E Couacaud | 7$^7$ | 5 | 6 | | | | | | | | | | |
| Q | T van Rijthoven | 6 | 6 | | Q | T van Rijthoven | 6$^4$ | 7 | 2 | | | | | | | | | | |
| Q | Omar Giacalone | 2 | 2 | | | | | | | 3 | E Couacaud | 6 | 6$^5$ | 6 | | | | | |
| | A Collarini | 6 | 6 | | | | | | | 8 | B Fratangelo | 1 | 7$^7$ | 3 | | | | | |
| | M Copil | 2 | 1 | | | A Collarini | 6 | 6$^2$ | 0$^r$ | | | | | | | | | | |
| | C İlkel | 2 | 4 | | 8 | B Fratangelo | 1 | 7$^7$ | 3 | | | | | | | | | | |
| 8 | B Fratangelo | 6 | 6 | | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | A Bolt | 7$^9$ | 1 | 3 | | | | | | | | | | | | | | |
| WC | S Napolitano | 6$^7$ | 6 | 6 | WC | S Napolitano | 3 | 4 | | | | | | | | | | |
| | D Istomin | 6 | 2 | 3 | | T Kokkinakis | 6 | 6 | | | | | | | | | | |
| | T Kokkinakis | 3 | 6 | 6 | | | | | | | T Kokkinakis | 6 | 7$^7$ | | | | | |
| | R Cid Subervi | 5 | 3 | | | | | | | 4 | A Müller | 4 | 6$^1$ | | | | | |
| Q | R Bonadio | 7 | 6 | | Q | R Bonadio | 0 | 6$^4$ | | | | | | | | | | |
| | M Viola | 6 | 3 | 1 | 4 | A Müller | 6 | 7$^7$ | | | | | | | | | | |
| 4 | A Müller | 4 | 6 | 6 | | | | | | | | | | | T Kokkinakis | 6 | 4 | 6 |
| 5 | D Popko | 2 | 6 | 6$^2$ | | | | | | | | | | 2 | Zh Zhang | 2 | 6 | 3 |
| | T-S Kwiatkowski | 6 | 1 | 7$^7$ | | T-S Kwiatkowski | 6 | 7$^7$ | | | | | | | | | | |
| | E Benchetrit | 4 | 4 | | | U Blanch | 4 | 6$^3$ | | | | | | | | | | |
| | U Blanch | 6 | 6 | | | | | | | | T-S Kwiatkowski | 4 | 6$^5$ | | | | | |
| | M Krueger | 4 | 3 | | | | | | | 2 | Zh Zhang | 6 | 7$^7$ | | | | | |
| WC | F Cobolli | 6 | 6 | | WC | F Cobolli | 6 | 4 | 2 | | | | | | | | | |
| | B Gojo | 3 | 6 | 2 | 2 | Zh Zhang | 4 | 6 | 6 | | | | | | | | | |
| 2 | Zh Zhang | 6 | 4 | 6 | | | | | | | | | | | | | | |