Dylan Alcott defeated Niels Vink in the final, 7–5, 6–2 to win the quad singles wheelchair tennis title at the 2021 US Open. With the win, Alcott completed the Golden Slam, becoming the first wheelchair tennis player to do so (alongside Diede de Groot in the women's singles event).
| Wheelchair quad singles | |
|---|---|
| 2021 US Open | |
| Champion |  Dylan Alcott |
| Runner-up |  Niels Vink |
| Score | 7–5, 6–2 |
Sam Schröder was the defending champion,[1] but was defeated in the quarterfinals by Vink. This was the first time that the quad singles used a knockout format at the US Open.
Seeds
edit- Dylan Alcott (champion)
- Sam Schröder (quarterfinals)
Draw
editKey
edit- 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
edit| Quarterfinals | Semifinals | Final | ||||||||||||||||||
| 1 | Dylan Alcott
| 6 | 6 | |||||||||||||||||
| WC |  Bryan Barten
| 0 | 1 | |||||||||||||||||
| 1 | Dylan Alcott
| 6 | 6 | |||||||||||||||||
 Koji Sugeno
| 2 | 1 | ||||||||||||||||||
| Koji Sugeno
| 6 | 4 | 6 | |||||||||||||||||
| David Wagner
| 4 | 6 | 4 | |||||||||||||||||
| 1 | Dylan Alcott
| 7 | 6 | |||||||||||||||||
| Niels Vink
| 5 | 2 | ||||||||||||||||||
| Heath Davidson
| 5 | 1 | ||||||||||||||||||
 Andy Lapthorne
| 7 | 6 | ||||||||||||||||||
| Andy Lapthorne
| 65 | 1 | ||||||||||||||||||
| Niels Vink
| 77 | 6 | ||||||||||||||||||
| Niels Vink
| 77 | 6 | ||||||||||||||||||
| 2 | Sam Schröder
| 65 | 4 | |||||||||||||||||