2021 Sparkassen Open

Country	Player	Rank1	Seed
FRA	Benoît Paire	46	1
LTU	Ričardas Berankis	80	2
GER	Yannick Hanfmann	99	3
SVK	Jozef Kovalík	127	4
SUI	Henri Laaksonen	137	5
CZE	Tomáš Macháč	144	6
IND	Sumit Nagal	150	7
GER	Daniel Altmaier	166	8

• ¹ Rankings are as of 28 June 2021.^[1]

The following players received wildcards into the singles main draw:

• Rudolf Molleker
• Marvin Möller
• Benoît Paire

The following players received entry into the singles main draw as alternates:

• Malek Jaziri
• Mischa Zverev

The following players received entry from the qualifying draw:

• Sandro Ehrat
• Dayne Kelly
• Daniel Michalski
• Mats Rosenkranz

The following player received entry as a lucky loser:

• Benjamin Hassan

• Daniel Altmaier def. Henri Laaksonen 6–1, 6–2.

• Szymon Walków / Jan Zieliński def. Ivan Sabanov / Matej Sabanov 6–4, 4–6, [10–4].