The 2021 MercedesCup was a men's tennis tournament played on outdoor grass courts. It was the 43rd edition of the Stuttgart Open, and part of the ATP Tour 250 series of the 2021 ATP Tour. It was held at the Tennis Club Weissenhof in Stuttgart, Germany, from 8 June until 13 June 2021. Unseeded Marin Čilić won the singles title.
Finals
Singles
Marin Čilić defeated 
Félix Auger-Aliassime, 7–6(7–2), 6–3
Doubles
Marcelo Demoliner / 
Santiago González defeated 
Ariel Behar / 
Gonzalo Escobar, 4–6, 6–3, [10–8]
Points and prize money
Point distribution
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Q | Q2 | Q1 |
| Singles | 250 | 150 | 90 | 45 | 20 | 0 | 12 | 6 | 0 |
|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 | — | — | — | — |
Prize money
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Q2 | Q1 |
| Singles | €53,280 | €38,200 | €27,195 | €18,130 | €11,660 | €7,010 | €3,425 | €1,780 |
| Doubles* | €19,880 | €14,240 | €9,390 | €6,090 | €3,580 | — | — | — |
*per team
ATP singles main draw entrants
Seeds
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| CAN
|
Denis Shapovalov | 14 | 1 |
 POL
|
Hubert Hurkacz | 17 | 2 |
| CAN
|
Félix Auger-Aliassime | 21 | 3 |
 AUS
|
Alex de Minaur | 22 | 4 |
 GEO
|
Nikoloz Basilashvili | 30 | 5 |
 FRA
|
Ugo Humbert | 31 | 6 |
| FRA
|
Adrian Mannarino | 36 | 7 |
| AUS |
- 1 Rankings are as of 31 May 2021.[3]
Other entrants
The following players received wildcards into the main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Withdrawals
- Before the tournament
Alexander Bublik → replaced by Alexei Popyrin
Taylor Fritz → replaced by Marin Čilić
Cristian Garín → replaced by Jordan Thompson
Aslan Karatsev → replaced by Jérémy Chardy- Reilly Opelka → replaced by
Lloyd Harris - Benoît Paire → replaced by Sam Querrey
- Milos Raonic → replaced by
Márton Fucsovics 
Jannik Sinner → replaced by 
Dominik Koepfer- Lorenzo Sonego → replaced by
Guido Pella - Jan-Lennard Struff → replaced by
Feliciano López 
Stan Wawrinka → replaced by 
Ilya Ivashka- Alexander Zverev → replaced by Gilles Simon
Retirements
ATP doubles main draw entrants
Seeds
| Country | Player | Country | Player | Rank1 | Seed |
|---|---|---|---|---|---|
 GBR
|
Jamie Murray | BRA
|
Bruno Soares | 33 | 1 |
| FRA
|
Jérémy Chardy | FRA
|
Fabrice Martin | 58 | 2 |
| RSA
|
Raven Klaasen |  JPN
|
Ben McLachlan | 67 | 3 |
 NZL
|
Marcus Daniell |  AUT
|
Philipp Oswald | 75 | 4 |
- 1 Rankings are as of 31 May 2021.
Other entrants
The following pairs received wildcards into the doubles main draw:
The following pairs received entry as alternates:
- Félix Auger-Aliassime / Nicholas Monroe
- Nikoloz Basilashvili /
Divij Sharan - Ariel Behar / Gonzalo Escobar
- Marcelo Demoliner / Santiago González
- Máximo González / Andrés Molteni
- Hubert Hurkacz / Łukasz Kubot
- Oliver Marach /
Aisam-ul-Haq Qureshi 
Frederik Nielsen / 
Jean-Julien Rojer- Luke Saville / Jordan Thompson
Withdrawals
- Before the tournament
- Rohan Bopanna / Franko Škugor → replaced by Oliver Marach / Aisam-ul-Haq Qureshi
- Alexander Bublik / Reilly Opelka → replaced by Ariel Behar / Gonzalo Escobar
Sander Gillé / Joran Vliegen → replaced by Máximo González / Andrés Molteni- Wesley Koolhof / Jean-Julien Rojer → replaced by Frederik Nielsen / Jean-Julien Rojer
- Sebastian Korda / Rajeev Ram → replaced by Marcelo Demoliner / Santiago González
- Kevin Krawietz / John Peers → replaced by Félix Auger-Aliassime / Nicholas Monroe
- Łukasz Kubot / Marcelo Melo → replaced by Hubert Hurkacz / Łukasz Kubot
- Adrian Mannarino / Benoît Paire → replaced by Nikoloz Basilashvili / Divij Sharan
- Tim Pütz / Michael Venus → replaced by Luke Saville / Jordan Thompson
- During the tournament
References
- ^ "2021 Stuttgart – Singles draw". Association of Tennis Professionals (ATP).
- ^ "2021 Stuttgart – Doubles draw". Association of Tennis Professionals (ATP).
- ^ "MercedesCup 2021: Nick Kyrgios confirms start, Zverev and Sinner are waiting for Paris". tennisnet.com. 11 May 2021.