# 2021 Stockholm Open – Singles

Tommy Paul defeated defending champion Denis Shapovalov in the final, 6–4, 2–6, 6–4, to win the singles tennis title at the 2021 Stockholm Open. It was Paul's first ATP Tour title.

## Seeds

The top four seeds receive a bye into the second round.
* Jannik Sinner (second round)
* Félix Auger-Aliassime (semifinals)
* Denis Shapovalov (final)
* Dan Evans (quarterfinals)
* Taylor Fritz (second round)
* Alexander Bublik (first round, retired)
* Márton Fucsovics (second round)
* Frances Tiafoe (semifinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| | Tommy Paul | 5 | 7$^7$ | 6 | | | | | |
| 8 | Frances Tiafoe | 7 | 6$^5$ | 4 | | | | | |
| 8 | Frances Tiafoe | 7 | 6$^5$ | 4 | | Tommy Paul | 6 | 2 | 6 |
| | | | | | 3 | Denis Shapovalov | 4 | 6 | 4 |
| 3 | Denis Shapovalov | 6 | 7 | | 3 | Denis Shapovalov | 4 | 6 | 4 |
| 2 | Félix Auger-Aliassime | 4 | 5 | | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| | | | | | 1 | J Sinner | 6$^4$ | 3 | | | | | | | | | | |
| WC | A Murray | 6 | 7$^9$ | | WC | A Murray | 7$^7$ | 6 | | | | | | | | | | |
| Q | V Durasovic | 1 | 6$^7$ | | | | | | WC | A Murray | 2 | 6 | 3 | | | | | |
| WC | L Borg | 4 | 2 | | | | | | | T Paul | 6 | 3 | 6 | | | | | |
| | T Paul | 6 | 6 | | | T Paul | 6 | 6 | | | | | | | | | | |
| LL | E Gerasimov | 4 | 4 | | 5 | T Fritz | 4 | 4 | | | | | | | | | | |
| 5 | T Fritz | 6 | 6 | | | | | | | | | | | | T Paul | 5 | 7$^7$ | 6 |
| | | | | | | | | | | | | | | 8 | F Tiafoe | 7 | 6$^5$ | 4 |
| | | | | | 4 | D Evans | 7$^7$ | 6 | | | | | | | | | | |
| | A Davidovich Fokina | 6 | 3 | 7 | | A Davidovich Fokina | 6$^5$ | 2 | | | | | | | | | | |
| | M McDonald | 2 | 6 | 5 | | | | | 4 | D Evans | 6 | 1 | 1 | | | | | |
| | P Martínez | 6 | 3 | 7$^7$ | | | | | 8 | F Tiafoe | 1 | 6 | 6 | | | | | |
| | E Ruusuvuori | 4 | 6 | 6$^4$ | | P Martínez | 4 | 4 | | | | | | | | | | |
| WC | E Ymer | 4 | 6$^2$ | | 8 | F Tiafoe | 6 | 6 | | | | | | | | | | |
| 8 | F Tiafoe | 6 | 7$^7$ | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | A Bublik | 1 | 0$^r$ | | | | | | | | | | | | | | | |
| | A Rinderknech | 6 | 2 | | | A Rinderknech | 6 | 6 | | | | | | | | | | |
| | P Gojowczyk | 7$^7$ | 4 | 5 | LL | J Kovalík | 4 | 1 | | | | | | | | | | |
| LL | J Kovalík | 6$^5$ | 6 | 7 | | | | | | | A Rinderknech | 6 | 3 | 5 | | | | |
| Q | A Vavassori | 6 | 6 | | | | | | | 3 | D Shapovalov | 4 | 6 | 7 | | | | |
| Q | P Kotov | 3 | 4 | | Q | A Vavassori | 6$^1$ | 1 | | | | | | | | | | |
| | | | | | 3 | D Shapovalov | 7$^7$ | 6 | | | | | | | | | | |
| | | | | | | | | | | | | | | | 3 | D Shapovalov | 6 | 7 |
| 7 | M Fucsovics | 6 | 6 | | | | | | | | | | | | 2 | F Auger-Aliassime | 4 | 5 |
| | A Mannarino | 4 | 0 | | 7 | M Fucsovics | 6$^3$ | 6 | 5 | | | | | | | | | |
| | B van de Zandschulp | 7$^7$ | 7$^7$ | | | B van de Zandschulp | 7$^7$ | 3 | 7 | | | | | | | | | |
| LL | N Serdarušić | 6$^5$ | 6$^5$ | | | | | | | | B van de Zandschulp | 4 | 3 | | | | | |
| Q | D Istomin | 4 | 2 | | | | | | | 2 | F Auger-Aliassime | 6 | 6 | | | | | |
| | F Krajinović | 6 | 6 | | | F Krajinović | 3 | 4 | | | | | | | | | | |
| | | | | | 2 | F Auger-Aliassime | 6 | 6 | | | | | | | | | | |

## Qualifying
### Seeds

* Egor Gerasimov (qualifying competition, lucky loser)
* Jozef Kovalík (qualifying competition, lucky loser)
* Nikola Milojević (first round)
* Mohamed Safwat (first round)
* Nino Serdarušić (qualifying competition, lucky loser)
* Denis Istomin (qualified)
* Teymuraz Gabashvili (first round)
* Pavel Kotov (qualified)

### Qualifiers

* Pavel Kotov
* Denis Istomin
* Andrea Vavassori
* Viktor Durasovic

### Lucky losers

* Egor Gerasimov
* Jozef Kovalík
* Nino Serdarušić

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Egor Gerasimov | 3 | 6 | 7 | | | | |
| | Matteo Martineau | 6 | 4 | 5 | | | | |
| | Matteo Martineau | 6 | 4 | 5 | 1 | Egor Gerasimov | 6$^4$ | 3 |
| | | | | | 8 | Pavel Kotov | 7$^7$ | 6 |
| | Raúl Brancaccio | 4 | 4 | | 8 | Pavel Kotov | 7$^7$ | 6 |
| 8 | Pavel Kotov | 6 | 6 | | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Jozef Kovalík | 7$^7$ | 7$^8$ | | | | | |
| | Danilo Petrović | 6$^2$ | 6$^6$ | | | | | |
| | Danilo Petrović | 6$^2$ | 6$^6$ | | 2 | Jozef Kovalík | 4 | 5 |
| | | | | | 6 | Denis Istomin | 6 | 7 |
| WC | Jonathan Mridha | 6 | 3 | 4 | 6 | Denis Istomin | 6 | 7 |
| 6 | Denis Istomin | 2 | 6 | 6 | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Nikola Milojević | 7$^7$ | 4 | 6$^7$ | | | | | |
| | Andrea Vavassori | 6$^4$ | 6 | 7$^9$ | | | | | |
| | Andrea Vavassori | 6$^4$ | 6 | 7$^9$ | | Andrea Vavassori | 3 | 6 | 6 |
| | | | | | 5 | Nino Serdarušić | 6 | 3 | 4 |
| WC | Simon Freund | 1 | 7$^7$ | 3 | 5 | Nino Serdarušić | 6 | 3 | 4 |
| 5 | Nino Serdarušić | 6 | 6$^1$ | 6 | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Mohamed Safwat | 4 | 6$^4$ | | | | |
| | Adrián Menéndez Maceiras | 6 | 7$^7$ | | | | |
| | Adrián Menéndez Maceiras | 6 | 7$^7$ | | Adrián Menéndez Maceiras | 3 | 2 |
| | | | | | Viktor Durasovic | 6 | 6 |
| | Viktor Durasovic | 6 | 3 | 6 | Viktor Durasovic | 6 | 6 |
| 7 | Teymuraz Gabashvili | 4 | 6 | 3 | | | |