| 2021 Meerbusch Challenger | |
|---|---|
| Date | 9–15 August |
| Edition | 8th |
| Surface | Clay |
| Location | Meerbusch, Germany |
| Champions | |
| Singles | |
 Marcelo Tomás Barrios Vera | |
| Doubles | |
 Szymon Walków / Jan Zieliński | |
The 2021 Rhein Asset Open presented by B&B Hotels was a professional tennis tournament played on clay courts. It was the eighth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Meerbusch, Germany, between 9 and 15 August 2021.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 GER | Daniel Altmaier | 120 | 1 |
 BIH | Damir Džumhur | 121 | 2 |
 NED | Botic van de Zandschulp | 126 | 3 |
| GER | Oscar Otte | 140 | 4 |
 ARG | Juan Manuel Cerúndolo | 145 | 5 |
 CZE | Tomáš Macháč | 150 | 6 |
 SVK | |||
 IND | Sumit Nagal | 159 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Marcelo Tomás Barrios Vera def. Juan Manuel Cerúndolo 7–6(9–7), 6–3. Szymon Walków / Jan Zieliński def. Dustin Brown / Robin Haase 6–3, 6–1.
