# 2021 Città di Como Challenger – Singles

Facundo Mena was the defending champion but chose not to defend his title.
Juan Manuel Cerúndolo won the title after defeating Gian Marco Moroni 7–5, 7–6$^{(9–7)}$ in the final.

## Seeds

* Daniel Altmaier (semifinals, retired)
* Jozef Kovalík (quarterfinals)
* Andrej Martin (second round)
* Juan Manuel Cerúndolo (champion)
* Federico Gaio (second round)
* Sumit Nagal (first round)
* Marc-Andrea Hüsler (first round)
* Alessandro Giannessi (withdrew)

## 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 |
| 1 | Daniel Altmaier | 4 | 0$^r$ | | | | | |
| 4 | Juan Manuel Cerúndolo | 6 | 3 | | | | | |
| 4 | Juan Manuel Cerúndolo | 6 | 3 | | 4 | Juan Manuel Cerúndolo | 7 | 7$^9$ |
| | | | | | | Gian Marco Moroni | 5 | 6$^7$ |
| | Gian Marco Moroni | 6 | 3 | 4 | | Gian Marco Moroni | 5 | 6$^7$ |
| Q | Andrea Vavassori | 3 | 6 | 0$^r$ | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | D Altmaier | 6 | 6 | | | | | | | | | | | | | |
| | J Domingues | 2 | 0 | | 1 | D Altmaier | 6 | 7 | | | | | | | | |
| | J Menezes | 4 | | | | J Menezes | 0 | 5 | | | | | | | | |
| Alt | E Furness | 1$^r$ | | | | | | | 1 | D Altmaier | 7$^7$ | 6 | | | | |
| WC | Federico Iannaccone | 5 | 6 | 6 | | | | | | R Bonadio | 6$^3$ | 3 | | | | |
| SE | C Ugo Carabelli | 7 | 3 | 4 | WC | F Iannaccone | 2 | 1 | | | | | | | | |
| | R Bonadio | 3 | 6 | 6 | | R Bonadio | 6 | 6 | | | | | | | | |
| Q | A Erler | 6 | 3 | 3 | | | | | | | | | 1 | D Altmaier | 4 | 0$^r$ |
| 4 | JM Cerúndolo | 6 | 7$^7$ | | | | | | | | | | 4 | JM Cerúndolo | 6 | 3 |
| | T Lamasine | 4 | 6$^2$ | | 4 | JM Cerúndolo | 5 | | | | | | | | | |
| Q | L Miedler | 6 | 2 | 4 | Alt | G Zeppieri | 0$^r$ | | | | | | | | | |
| Alt | G Zeppieri | 4 | 6 | 6 | | | | | 4 | JM Cerúndolo | 7 | 6 | | | | |
| PR | J Cagnina | 1 | 3$^r$ | | | | | | SE | N Serdarušić | 5 | 2 | | | | |
| WC | F Cobolli | 6 | 3 | | WC | F Cobolli | 4 | 0 | | | | | | | | |
| SE | N Serdarušić | 6 | 6 | | SE | N Serdarušić | 6 | 6 | | | | | | | | |
| 7 | M-A Hüsler | 4 | 3 | | | | | | | | | | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | F Gaio | 6 | 3 | 6 | | | | | | | | | | | | | | | |
| Q | P Chrysochos | 1 | 6 | 3 | 5 | F Gaio | 5 | 1 | | | | | | | | | | | |
| LL | A Vatutin | 0$^r$ | | | | GM Moroni | 7 | 6 | | | | | | | | | | | |
| | GM Moroni | 3 | | | | | | | | | GM Moroni | 6 | 4 | 6 | | | | | |
| PR | A Arnaboldi | 7$^7$ | 6 | | | | | | | PR | A Arnaboldi | 3 | 6 | 2 | | | | | |
| | T Gabashvili | 6$^5$ | 2 | | PR | A Arnaboldi | 4 | 6 | 6 | | | | | | | | | | |
| WC | F Forti | 7 | 2 | 1 | 3 | A Martin | 6 | 4 | 3 | | | | | | | | | | |
| 3 | A Martin | 5 | 6 | 6 | | | | | | | | | | | | GM Moroni | 6 | 3 | 4 |
| 6 | S Nagal | 4 | 6$^4$ | | | | | | | | | | | | Q | A Vavassori | 3 | 6 | 0$^r$ |
| | A Kuznetsov | 6 | 7$^7$ | | | A Kuznetsov | 6 | 3 | 4 | | | | | | | | | | |
| | J Draper | 4 | 6 | 3 | Q | A Vavassori | 2 | 6 | 6 | | | | | | | | | | |
| Q | A Vavassori | 6 | 2 | 6 | | | | | | Q | A Vavassori | 6 | 6 | | | | | | |
| | N Borges | 3 | 1 | | | | | | | 2 | J Kovalík | 3 | 4 | | | | | | |
| LL | F Agamenone | 6 | 6 | | LL | F Agamenone | 2 | 6$^1$ | | | | | | | | | | | |
| PR | J Lenz | 5 | 2 | | 2 | J Kovalík | 6 | 7$^7$ | | | | | | | | | | | |
| 2 | J Kovalík | 7 | 6 | | | | | | | | | | | | | | | | |