| Singles | |
|---|---|
| 2021 Cleveland Open | |
| Champion |  Bjorn Fratangelo |
| Runner-up | Jenson Brooksby |
| Score | 7–5, 6–4 |
Mikael Torpegaard was the defending champion [1] but lost in the first round to Lucas Catarina.
Bjorn Fratangelo won the title after defeating Jenson Brooksby 7–5, 6–4 in the final.
James Duckworth (first round)
Go Soeda (first round)
Emilio Gómez (semifinals)
Mikael Torpegaard (first round) Mitchell Krueger (first round)
Brayden Schnur (second round) Thai-Son Kwiatkowski (first round)
Roberto Cid Subervi (first round)| Semifinals | Final | ||||||||||||
| Jenson Brooksby | 2 | 7 | 6 | ||||||||||
| 3 | Emilio Gómez | 6 | 5 | 4 | |||||||||
| Jenson Brooksby | 5 | 4 | |||||||||||
| Bjorn Fratangelo | 7 | 6 | |||||||||||
| Q | Aleksandar Kovacevic | 3 | 6 | 1 | |||||||||
| Bjorn Fratangelo | 6 | 2 | 6 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | J Duckworth | 611 | 1 | ||||||||||||||||||||||||
| Mi Redlicki | 713 | 6 | Mi Redlicki | 6 | 6 | ||||||||||||||||||||||
| WC | L Draxl | 78 | 6 | WC | L Draxl | 3 | 3 | ||||||||||||||||||||
| R Quiroz | 66 | 4 | Mi Redlicki | 65 | 4 | ||||||||||||||||||||||
| J Brooksby | 77 | 77 | J Brooksby | 77 | 6 | ||||||||||||||||||||||
| WC | Z Svajda | 64 | 65 | J Brooksby | 6 | 77 | |||||||||||||||||||||
| Q | Felix Corwin | 60 | 64 | 6 | B Schnur | 2 | 65 | ||||||||||||||||||||
| 6 | B Schnur | 77 | 77 | J Brooksby | 2 | 7 | 6 | ||||||||||||||||||||
| 3 | E Gómez | 6 | 6 | 3 | E Gómez | 6 | 5 | 4 | |||||||||||||||||||
| Alt | E King | 4 | 2 | 3 | E Gómez | 1 | 77 | 6 | |||||||||||||||||||
| Alt |  N Mejía | 6 | 4 | 6 | Alt | N Mejía | 6 | 64 | 1 | ||||||||||||||||||
| Q | Evan Song | 3 | 6 | 3 | 3 | E Gómez | 6 | 6 | |||||||||||||||||||
| H Moriya | 6 | 4 | 2 | C Eubanks | 3 | 3 | |||||||||||||||||||||
| C Eubanks | 4 | 6 | 6 | C Eubanks | 6 | 6 | |||||||||||||||||||||
 D King | 6 | 5 | 7 | D King | 1 | 2 | |||||||||||||||||||||
| 5 | M Krueger | 3 | 7 | 5 | |||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 8 | R Cid Subervi | 2 | 4 | ||||||||||||||||||||||||
| Q | A Kovacevic | 6 | 6 | Q | A Kovacevic | 77 | 6 | ||||||||||||||||||||
| N Chappell | 4 | 7 | 4 | WC | R Smith | 64 | 3 | ||||||||||||||||||||
| WC | Roy Smith | 6 | 5 | 6 | Q | A Kovacevic | 5 | 6 | 6 | ||||||||||||||||||
| K King | 4 | 61 | Yo Watanuki | 7 | 2 | 3 | |||||||||||||||||||||
| Yo Watanuki | 6 | 77 | Yo Watanuki | 6 | 5 | 6 | |||||||||||||||||||||
| Alt |  L Catarina | 5 | 6 | 6 | Alt | L Catarina | 3 | 7 | 1 | ||||||||||||||||||
| 4 | M Torpegaard | 7 | 3 | 4 | Q | A Kovacevic | 3 | 6 | 1 | ||||||||||||||||||
| 7 | T-S Kwiatkowski | 4 | 2 | B Fratangelo | 6 | 2 | 6 | ||||||||||||||||||||
| B Fratangelo | 6 | 6 | B Fratangelo | 6 | 6 | ||||||||||||||||||||||
| A Ritschard | 77 | 5 | 7 | A Ritschard | 3 | 2 | |||||||||||||||||||||
| JC Aragone | 65 | 7 | 5 | B Fratangelo | 6 | 5 | |||||||||||||||||||||
| Q | A Galarneau | 6 | 6 | Q | A Galarneau | 3 | 0r | ||||||||||||||||||||
| Shuichi Sekiguchi | 3 | 1 | Q | A Galarneau | 7 | 7 | |||||||||||||||||||||
| D Young | 6 | 65 | 7 | D Young | 5 | 5 | |||||||||||||||||||||
| 2 | G Soeda | 3 | 77 | 5 | |||||||||||||||||||||||
Dennis Novikov was the defending champion but lost in the first round to Evan King.
Mikael Torpegaard was the defending champion but lost in the first round to Taylor Fritz.
Michael Mmoh was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
Denis Kudla was the defending champion but chose not to defend his title.
Noah Rubin was the defending champion but lost in the quarterfinals to Tennys Sandgren.
J. J. Wolf was the defending champion but lost in the second round to Nam Ji-sung.
Jason Kubler was the defending champion but chose not to defend his title.
Bradley Klahn was the defending champion but chose not to defend his title.
Nick Kyrgios defeated Daniil Medvedev in the final, 7–6(8–6), 7–6(7–4) to win the men's singles tennis title at the 2019 Washington Open. Kyrgios saved a match point in the semifinals against Stefanos Tsitsipas.
This was the first edition of the tournament.
James Duckworth was the defending champion but chose not to defend his title.
Mikael Torpegaard was the defending champion but lost in the quarterfinals to Roberto Quiroz.
Michael Mmoh was the defending champion but lost in the second round to Brandon Nakashima.
Reilly Opelka was the defending champion but chose not to defend his title.
Mikael Ymer was the defending champion but chose not to defend his title.
Maxime Cressy was the defending champion but lost in the third round to Ulises Blanch.
Peter Polansky was the defending champion but lost in the second round to Strong Kirchheimer.
Stefan Kozlov and Peter Polansky were the defending champions but withdrew from the tournament due to a Kozlov injury.
Tennys Sandgren and Mikael Torpegaard were the defending champions but chose not to defend their title.