| Champ: |  Daria Kasatkina |
| Runner: |  Marie Bouzková |
| Score: | 4–6, 6–2, 6–2 |
| Draw: | 56 |
| Seeds: | 16 |
| Edition: | 1st |
| Type: | singles doubles |
| Main Name: | Australian Open Series |
See main article: 2021 Phillip Island Trophy.
The Phillip Island Trophy was a new addition to the WTA Tour in 2021.[1]
Daria Kasatkina won the title, defeating Marie Bouzková in the final, 4–6, 6–2, 6–2.
The top eight seeds received a bye into the second round.
See also: 1 and 1. 
Sofia Kenin (second round)
See also: 2 and 4. 
Bianca Andreescu (semifinals)
See also: 3. 
Johanna Konta (withdrew)
See also: 4 and 2. Petra Martić (quarterfinals)
See also: 5 and 4. 
Wang Qiang (third round)
See also: 6. Zhang Shuai (withdrew)
See also: 7 and 2. Anastasia Pavlyuchenkova (third round)
See also: 8 and 1. Danielle Collins (semifinals)
See also: 9 and 2. Sloane Stephens (first round)
See also: 10 and 1. 
Caroline Garcia (first round)
See also: 11 and 3. Zheng Saisai (first round)
See also: 12 and 4. 
Nadia Podoroska (first round)
See also: 13 and 3. Marie Bouzková (final)
See also: 14 and 4. Anastasija Sevastova (first round)
See also: 15 and 2. Alizé Cornet (first round)
See also: 16 and 1. 
Rebecca Peterson (quarterfinals)