2021 Platzmann-Sauerland Open

Country	Player	Rank1	Seed
ESP	Pablo Andújar	74	1
ESP	Pedro Martínez	76	2
ESP	Roberto Carballés Baena	96	3
GER	Daniel Altmaier	124	4
BOL	Hugo Dellien	142	5
ARG	Juan Manuel Cerúndolo	148	6
RUS	Roman Safiullin	162	7
NED	Robin Haase	226	8
FRA	Constant Lestienne	245	9

• ¹ Rankings as of 9 August 2021.^[1]

The following players received wildcards into the singles main draw:

• Shintaro Mochizuki
• Rudolf Molleker
• Marvin Möller

The following player received entry into the singles main draw using a protected ranking:

• Julien Cagnina

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

• Nicolás Kicker
• Jelle Sels

The following players received entry from the qualifying draw:

• Javier Barranco Cosano
• Filip Jianu
• Matteo Martineau
• Genaro Alberto Olivieri

• Daniel Altmaier def. Nicolás Jarry 7–6^(7–1), 4–6, 6–3.

• Ivan Sabanov / Matej Sabanov def. Denys Molchanov / Aleksandr Nedovyesov 6–4, 2–6, [12–10].