2021 Slovak Open II

Country	Player	Rank1	Seed
ITA	Stefano Travaglia	81	1
NED	Tallon Griekspoor	88	2
ESP	Carlos Taberner	95	3
SVK	Norbert Gombos	110	4
SVK	Alex Molčan	114	5
FRA	Gilles Simon	120	6
GBR	Liam Broady	121	7
CZE	Tomáš Macháč	134	8

• ¹ Rankings are as of 1 November 2021.^[1]

The following players received wildcards into the singles main draw:

• Jonáš Forejtek
• Lukáš Palovič
• Lukáš Pokorný

The following player received entry into the singles main draw as an alternate:

• Tobias Kamke

The following players received entry from the qualifying draw:

• Danylo Kalenichenko
• Miloš Karol
• Zsombor Piros
• Dalibor Svrčina

The following players received entry as lucky losers:

• Shintaro Mochizuki
• Alexander Shevchenko

• Tallon Griekspoor def. Zsombor Piros 6–3, 6–2.

• Filip Horanský / Sergiy Stakhovsky def. Denys Molchanov / Aleksandr Nedovyesov 6–4, 6–4.