The 2021 Svijany Open was a professional tennis tournament played on clay courts. It was the 8th edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Liberec, Czech Republic between 2 and 8 August 2021.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Czech Republic | ||||
| Tallon Griekspoor | 107 | 2 | ||
 Poland | Kamil Majchrzak | 114 | 3 | |
 Slovakia | Andrej Martin | 116 | 4 | |
| Botic van de Zandschulp | 126 | 5 | ||
 Australia | Marc Polmans | 144 | 6 | |
| Czech Republic | Tomáš Macháč | 148 | 7 | |
| Slovakia | Alex Molčan | 150 | 8 |
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw using a protected ranking:
The following player received entry into the singles main draw as a special exempt:
The following player received entry into the singles main draw as an alternate:
The following players received entry from the qualifying draw:
Evan Furness
Nikola Milojević
Alexander Ritschard Daniel SiniakovThe following player received entry as a lucky loser:
See main article: 2021 Svijany Open – Singles.
Alex Molčan def. Tomáš Macháč 6–0, 6–1.See main article: 2021 Svijany Open – Doubles.
Roman Jebavý / Igor Zelenay def. Geoffrey Blancaneaux / Maxime Janvier 6–2, 6–7(6–8), [10–5].
