| Champ: |  Dan Evans |
| Runner: |  Félix Auger-Aliassime |
| Score: | 6–2, 6–3 |
| Edition: | 1st |
| Type: | singles doubles |
| Main Name: | Australian Open Series |
See main article: 2021 Murray River Open.
The Murray River Open was a new addition to the ATP Tour in 2021.
Dan Evans won his maiden ATP title, defeating Félix Auger-Aliassime in the final, 6–2, 6–3. This was the seventh consecutive final loss of Auger-Aliassime's career.
The top eight seeds received a bye into the second round.
See also: 1 and 1. Stan Wawrinka (quarterfinals, withdrew)
See also: 2 and 4. Grigor Dimitrov (quarterfinals)
See also: 3 and 3. Félix Auger-Aliassime (final)
See also: 4 and 2. Borna Ćorić (quarterfinals)
See also: 5 and 3. 
Casper Ruud (second round)
See also: 6 and 1. 
Taylor Fritz (third round)
See also: 7 and 4. 
Ugo Humbert (second round)
See also: 8 and 2. Dan Evans (champion)
See also: 9 and 3. 
Lorenzo Sonego (first round)
See also: 10 and 2. Adrian Mannarino (second round)
See also: 11 and 1. Marin Čilić (first round)
See also: 12 and 4. 
Albert Ramos Viñolas (second round)
See also: 13 and 2. 
Nick Kyrgios (third round)
See also: 14 and 1. Richard Gasquet (first round)
See also: 15 and 4. Tommy Paul (second round)
See also: 16 and 3. 
Márton Fucsovics (second round)