# 2021 Biella Challenger VII – Singles

Thanasi Kokkinakis was the defending champion but chose not to defend his title.
Holger Rune won the title after defeating Marco Trungelliti 6–3, 5–7, 7–6$^{(7–5)}$ in the final.

## Seeds

* Juan Pablo Varillas (second round)
* Nikola Milojević (second round)
* Daniel Altmaier (first round)
* Danilo Petrović (first round, retired)
* Frederico Ferreira Silva (second round)
* Kacper Żuk (quarterfinals)
* Martin Kližan (second round)
* Lorenzo Giustino (second round)

## 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 | Final |
| | Felipe Meligeni Alves | 3 | 6 | 3 | | | | | |
| | Marco Trungelliti | 6 | 3 | 6 | | | | | |
| | Marco Trungelliti | 6 | 3 | 6 | | Marco Trungelliti | 3 | 7 | 6$^5$ |
| | | | | | SE | Holger Rune | 6 | 5 | 7$^7$ |
| SE | Holger Rune | 7 | 2 | 6 | SE | Holger Rune | 6 | 5 | 7$^7$ |
| | Tomás Martín Etcheverry | 5 | 6 | 2 | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | JP Varillas | 6 | 6 | | | | | | | | | | | | | | |
| | Z Kolář | 3 | 1 | | 1 | JP Varillas | 3 | 6$^1$ | | | | | | | | | |
| | R Olivo | 6 | 6 | | | R Olivo | 6 | 7$^7$ | | | | | | | | | |
| | J Menezes | 4 | 3 | | | | | | | | R Olivo | 3 | 3 | | | | |
| | R Marcora | 3 | 1 | | | | | | | | F Meligeni Alves | 6 | 6 | | | | |
| | F Meligeni Alves | 6 | 6 | | | F Meligeni Alves | 6 | 6 | | | | | | | | | |
| | A Collarini | 5 | 6 | 4 | 7 | M Kližan | 2 | 4 | | | | | | | | | |
| 7 | M Kližan | 7 | 2 | 6 | | | | | | | | | | F Meligeni Alves | 3 | 6 | 3 |
| 4 | D Petrović | 1 | 0$^r$ | | | | | | | | | | | M Trungelliti | 6 | 3 | 6 |
| Q | J Berrettini | 6 | 2 | | Q | J Berrettini | 5 | 6 | 6 | | | | | | | | |
| | R Ramanathan | 6 | 6 | | | R Ramanathan | 7 | 1 | 4 | | | | | | | | |
| | B Kavčič | 1 | 1 | | | | | | | Q | J Berrettini | 5 | 3 | | | | |
| | M Trungelliti | 6 | 6 | | | | | | | | M Trungelliti | 7 | 6 | | | | |
| Q | H Grenier | 0 | 2 | | | M Trungelliti | 6 | 6 | | | | | | | | | |
| WC | L Nardi | 6 | 4 | 1$^r$ | 8 | L Giustino | 4 | 2 | | | | | | | | | |
| 8 | L Giustino | 2 | 6 | 4 | | | | | | | | | | | | | |

### 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 |
| 5 | F Ferreira Silva | 6 | 7 | | | | | | | | | | | | | | | |
| | S Diez | 3 | 5 | | 5 | F Ferreira Silva | 6 | 6$^3$ | 2 | | | | | | | | | |
| | A Müller | 6 | 6 | | | A Müller | 3 | 7$^7$ | 6 | | | | | | | | | |
| WC | S Napolitano | 4 | 1 | | | | | | | | A Müller | 4 | 4 | | | | | |
| SE | G Elias | 1 | 6 | 6 | | | | | | SE | H Rune | 6 | 6 | | | | | |
| WC | F Cobolli | 6 | 3 | 4 | SE | G Elias | 3 | 6$^3$ | | | | | | | | | | |
| SE | H Rune | 6 | 6$^4$ | 7$^7$ | SE | H Rune | 6 | 7$^7$ | | | | | | | | | | |
| 3 | D Altmaier | 2 | 7$^7$ | 6$^5$ | | | | | | | | | | SE | H Rune | 7 | 2 | 6 |
| 6 | K Żuk | 6 | 6 | | | | | | | | | | | | TM Etcheverry | 5 | 6 | 2 |
| Q | R Brancaccio | 4 | 2 | | 6 | K Żuk | 7 | 7 | | | | | | | | | | |
| | A Pellegrino | 3 | 7 | 6 | | A Pellegrino | 5 | 5 | | | | | | | | | | |
| Q | C Ugo Carabelli | 6 | 5 | 1 | | | | | | 6 | K Żuk | 4 | 3 | | | | | |
| | M Janvier | 6 | 3 | 0 | | | | | | | TM Etcheverry | 6 | 6 | | | | | |
| | TM Etcheverry | 4 | 6 | 6 | | TM Etcheverry | 7 | 6 | | | | | | | | | | |
| | L Lacko | 2 | 3 | | 2 | N Milojević | 5 | 3 | | | | | | | | | | |
| 2 | N Milojević | 6 | 6 | | | | | | | | | | | | | | | |