# 2021 Svijany Open – Singles

Nikola Milojević was the defending champion but lost in the second round to Tomáš Macháč.
Alex Molčan won the title after defeating Macháč 6–0, 6–1 in the final.

## Seeds

* Jiří Veselý (withdrew)
* Tallon Griekspoor (first round)
* Kamil Majchrzak (quarterfinals)
* Andrej Martin (first round)
* Botic van de Zandschulp (semifinals)
* Marc Polmans (quarterfinals)
* Tomáš Macháč (final)
* Alex Molčan (champion)

## 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 | Final | Final | Final | Final |
| Alt | Malek Jaziri | 1 | 0 | | | | |
| 8 | Alex Molčan | 6 | 6 | | | | |
| 8 | Alex Molčan | 6 | 6 | 8 | Alex Molčan | 6 | 6 |
| | | | | 7 | Tomáš Macháč | 0 | 1 |
| 7 | Tomáš Macháč | 6 | 6 | 7 | Tomáš Macháč | 0 | 1 |
| 5 | Botic van de Zandschulp | 2 | 2 | | | | |

### 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 |
| LL | D Vega Hernández | 1 | 2 | | | | | | | | | | | | | |
| Alt | M Jaziri | 6 | 6 | | Alt | M Jaziri | 6 | 6 | | | | | | | | |
| | A Vukic | 2 | 5 | | | F Horanský | 4 | 3 | | | | | | | | |
| | F Horanský | 6 | 7 | | | | | | Alt | M Jaziri | 6 | 6 | | | | |
| | M Marterer | 6 | 6 | | | | | | 6 | M Polmans | 2 | 4 | | | | |
| | S Nagal | 4 | 3 | | | M Marterer | 4 | 4 | | | | | | | | |
| WC | M Vrbenský | 7$^7$ | 2 | 5 | 6 | M Polmans | 6 | 6 | | | | | | | | |
| 6 | M Polmans | 6$^5$ | 6 | 7 | | | | | | | | | Alt | M Jaziri | 1 | 0 |
| 3 | K Majchrzak | 6 | 6 | | | | | | | | | | 8 | A Molčan | 6 | 6 |
| | D Popko | 2 | 3 | | 3 | K Majchrzak | 6 | 6 | | | | | | | | |
| | JP Ficovich | 4 | 4 | | | M Safwat | 2 | 2 | | | | | | | | |
| | M Safwat | 6 | 6 | | | | | | 3 | K Majchrzak | 6$^3$ | 3 | | | | |
| WC | J Forejtek | 6$^4$ | 2 | | | | | | 8 | A Molčan | 7$^7$ | 6 | | | | |
| WC | D Svrčina | 7$^7$ | 6 | | WC | D Svrčina | 2 | 1 | | | | | | | | |
| | R Haase | 1 | 4 | | 8 | A Molčan | 6 | 6 | | | | | | | | |
| 8 | A Molčan | 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 |
| 7 | T Macháč | 3 | 6 | 6 | | | | | | | | | | | | | |
| | E Couacaud | 6 | 3 | 3 | 7 | T Macháč | 6 | 7$^9$ | | | | | | | | | |
| Q | N Milojević | 7 | 6 | | Q | N Milojević | 2 | 6$^7$ | | | | | | | | | |
| Q | Daniel Siniakov | 5 | 0 | | | | | | | 7 | T Macháč | 7$^{10}$ | 6 | | | | |
| Q | E Furness | 3 | 6 | 6 | | | | | | PR | G Melzer | 6$^8$ | 4 | | | | |
| SE | T van Rijthoven | 6 | 4 | 2 | Q | E Furness | 4 | 2 | | | | | | | | | |
| PR | G Melzer | 6 | 5 | 6 | PR | G Melzer | 6 | 6 | | | | | | | | | |
| 4 | A Martin | 3 | 7 | 4 | | | | | | | | | | 7 | T Macháč | 6 | 6 |
| 5 | B van de Zandschulp | 6 | 7 | | | | | | | | | | | 5 | B van de Zandschulp | 2 | 2 |
| | V Sachko | 3 | 5 | | 5 | B van de Zandschulp | 6 | 3 | 7 | | | | | | | | |
| | M Janvier | 3 | 4 | | | L Klein | 4 | 6 | 5 | | | | | | | | |
| | L Klein | 6 | 6 | | | | | | | 5 | B van de Zandschulp | 6 | 6 | | | | |
| Q | A Ritschard | 6 | 3 | 6 | | | | | | Q | A Ritschard | 2 | 3 | | | | |
| | J Lehečka | 4 | 6 | 1 | Q | A Ritschard | 5 | 7 | 6 | | | | | | | | |
| | B Gojo | 6 | 6 | | | B Gojo | 7 | 5 | 3 | | | | | | | | |
| 2 | T Griekspoor | 4 | 3 | | | | | | | | | | | | | | |