| Date: | July 12–18 |
| Edition: | 45th |
| Category: | ATP Tour 250 series |
| Surface: | Grass / outdoor |
| Location: | Newport, Rhode Island, United States |
| Venue: | International Tennis Hall of Fame |
| Champs: | Kevin Anderson |
| Champd: |  William Blumberg / Jack Sock |
| Before Year: | 2019 |
| Before Name: | Hall of Fame Tennis Championships |
The 2021 Hall of Fame Open was a men's tennis tournament played on outdoor grass courts. It was the 45th edition of the event, and part of the 250 series of the 2021 ATP Tour. It took place at the International Tennis Hall of Fame in Newport, Rhode Island, United States, from July 12 through July 18, 2021.[1]
See main article: 2021 Hall of Fame Open – Singles.
Jenson Brooksby, 7–6(10–8), 6–4See main article: 2021 Hall of Fame Open – Doubles.
William Blumberg / Jack Sock def. Austin Krajicek / 
Vasek Pospisil, 6–2, 7–6(7–3)| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles | 250 | 150 | 90 | 45 | 20 | 0 | 12 | 6 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| Singles | $45,795 | $32,835 | $23,375 | $15,580 | $10,015 | $6,030 | $2,945 | $1,530 | ||
| Doubles* | $17,100 | $12,240 | $8,070 | $5,240 | $3,070 |
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 Kazakhstan | Alexander Bublik | 38 | 1 |
| United States | Sam Querrey | 54 | 2 |
 Japan | Yoshihito Nishioka | 58 | 3 |
| Canada | Vasek Pospisil | 65 | 4 |
| United States | Tennys Sandgren | 68 | 5 |
| United States | Steve Johnson | 74 | 6 |
 Australia | Jordan Thompson | 78 | 7 |
| Kevin Anderson | 102 | 8 | |
The following players received wildcards into the main draw:
The following players received entry from the qualifying draw:
James Duckworth → replaced by Jenson Brooksby Marcos Giron → replaced by Jason Jung
Adrian Mannarino → replaced by Maxime Cressy Mackenzie McDonald → replaced by Cedrik-Marcel Stebe Tommy Paul → replaced by 
Jurij Rodionov
Andreas Seppi → replaced by Paolo Lorenzi| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 New Zealand | Marcus Daniell | Japan | Ben McLachlan | 88 | 1 | |
 Israel | Jonathan Erlich |  Mexico | Santiago González | 126 | 2 | |
 Finland | Harri Heliövaara | Australia | John-Patrick Smith | 156 | 3 | |
 United Kingdom | Australia |
The following pairs received wildcards into the doubles main draw:
The following pair received entry as alternates:
Matthew Ebden / John-Patrick Smith → replaced by Harri Heliövaara / John-Patrick Smith Harri Heliövaara / Lloyd Glasspool → replaced by Robert Galloway / Alex Lawson James Duckworth / Matt Reid → Yoshihito Nishioka / Yasutaka Uchiyama Marcos Giron / Evan King → replaced by Treat Huey / Miguel Ángel Reyes Varela