| Doubles | |
|---|---|
| 2021 Orlando Open II | |
| Champions |  Christian Harrison  Peter Polansky |
| Runners-up | JC Aragone  Nicolás Barrientos |
| Score | 6–2, 6–3 |
Mitchell Krueger and Jack Sock were the defending champions [1] but chose not to defend their title.
Christian Harrison and Peter Polansky won the title after defeating JC Aragone and Nicolás Barrientos 6–2, 6–3 in the final.
Robert Galloway / Alex Lawson (semifinals) Dennis Novikov / 
Gonçalo Oliveira (first round)
Jeevan Nedunchezhiyan / Purav Raja (first round) Christian Harrison / Peter Polansky (champions)| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | R Galloway A Lawson | 4 | 77 | [10] | |||||||||||||||||||||||
 B Arias JA Ore | 6 | 64 | [4] | 1 | R Galloway A Lawson | 6 | 6 | ||||||||||||||||||||
 R Gonzales Ma Redlicki | 6 | 77 | R Gonzales Ma Redlicki | 4 | 4 | ||||||||||||||||||||||
 E Leshem  H Moriya | 3 | 64 | 1 | R Galloway A Lawson | 65 | 7 | [4] | ||||||||||||||||||||
| 4 | C Harrison P Polansky | 6 | 6 | 4 | C Harrison P Polansky | 77 | 5 | [10] | |||||||||||||||||||
H Johnson  R Roelofse | 1 | 3 | 4 | C Harrison P Polansky | 2 | 6 | [10] | ||||||||||||||||||||
| S Bangoura D Young | 6 | 6 | S Bangoura D Young | 6 | 2 | [6] | |||||||||||||||||||||
 G Andreozzi A Velotti | 1 | 4 | 4 | C Harrison P Polansky | 6 | 6 | |||||||||||||||||||||
| JC Aragone N Barrientos | 6 | 6 | JC Aragone N Barrientos | 2 | 3 | ||||||||||||||||||||||
| Y Johnson Mi Redlicki | 2 | 1 | JC Aragone N Barrientos | 6 | 6 | ||||||||||||||||||||||
| WC | Jac Vance Tennyson Whiting | 6 | 3 | [10] | WC | Jac Vance T Whiting | 4 | 0 | |||||||||||||||||||
| 3 | J Nedunchezhiyan P Raja | 3 | 6 | [7] | JC Aragone N Barrientos | 77 | 6 | ||||||||||||||||||||
| WC |  N Álvarez N Chappell | 3 | 2 |  D King  J Kubler | 64 | 2 | |||||||||||||||||||||
| D King J Kubler | 6 | 6 | D King J Kubler | 6 | 77 | ||||||||||||||||||||||
| WC | Oliver Crawford S Riffice | 6 | 4 | [10] | WC | O Crawford S Riffice | 4 | 64 | |||||||||||||||||||
| 2 | D Novikov G Oliveira | 2 | 6 | [4] | |||||||||||||||||||||||
Michael Russell was the defending champion, but retired against Tennys Sandgren in the quarterfinals.
Top seed Tim Smyczek won the title defeating unseeded Canadian Peter Polansky in the final.
Rhyne Williams was the defending champion but lost in the quarterfinal to Malek Jaziri.
Alex Kuznetsov and Mischa Zverev were the defending champions but lost to Alex Bogomolov Jr. and Jordan Kerr in the quarterfinals.
Top seeded Australians Samuel Groth and Chris Guccione won the title over wildcards Ryan Harrison and Mark Knowles.
John Isner was the defending champion, but lost in the second round to Dustin Brown.
Ryan Harrison was the defending champion, but did not participate.
Frank Dancevic and Peter Polansky were the defending champions, but Dancevic chose not to compete.
Polansky paired with Adil Shamasdin and they won the title, defeating Chase Buchanan and James McGee in the final 6–4, 6–2.
Peter Polansky was the defending champion, but withdrew because of an elbow injury.
Kei Nishikori was the four-time defending champion, but chose to compete in Buenos Aires instead.
Brian Baker and Ryan Harrison were the defending champions but chose not to defend their title.
Go Soeda was the defending champion but chose not to defend his title.
Peter Polansky was the defending champion but lost in the final to Denis Shapovalov.
Frances Tiafoe was the defending champion but chose not to defend his title.
Scott Lipsky and Jürgen Melzer were the defending champions but only Lipsky chose to defend his title, partnering Donald Young. Lipsky lost in the first round to Christian Harrison and Peter Polansky.
Tennys Sandgren was the defending champion but chose not to defend his title.
Bradley Klahn and Jackson Withrow were the defending champions but only Klahn chose to defend his title, partnering Robert Galloway. Klahn successfully defended his title.
Blaž Kavčič was the defending champion but chose not to defend his title.
Juan Martín del Potro was the two-time defending champion but chose not to defend his title.
Christian Harrison and Dennis Novikov were the defending champions but lost in the semifinals to William Blumberg and Max Schnur.
Treat Huey and Nathaniel Lammons were the defending champions but chose not to defend their title.
Christian Harrison and Peter Polansky were the defending champions but only Harrison chose to defend his title, partnering Andrew Harris. Harrison lost in the semifinals to Chung Yun-seong and Michail Pervolarakis.