The 2021 Great Ocean Road Open was a tournament on the 2021 ATP Tour, one of six events in the 2021 Melbourne Summer Series. It was played on outdoor hard courts in Melbourne, Australia. It was organised as a lead-up tournament to the 2021 Australian Open, and was held at the same venue, due to other tournaments in Australia being cancelled as a result of the COVID-19 pandemic. This tournament took place simultaneously with the 2021 Murray River Open and the 2021 ATP Cup, and was considered a relocation of the men's 2021 Adelaide International.[1]
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Round of 64 |
| Singles | 250 | 150 | 90 | 45 | 20 | 10 | 0 |
|---|---|---|---|---|---|---|---|
| Doubles | 0 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Round of 64 | |
| Singles | $19,500 | $13,255 | $10,000 | $7,400 | $5,500 | $4,000 | $2,500 | |
| Doubles* | $7,200 | $5,760 | $4,560 | $3,360 | $2,160 | $1,200 |
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Belgium | David Goffin | 14 | 1 | |
 Russian Federation | Karen Khachanov | 20 | 2 | |
 Poland | Hubert Hurkacz | 29 | 3 | |
 Italy | Jannik Sinner | 36 | 4 | |
 Georgia | Nikoloz Basilashvili | 39 | 5 | |
| Reilly Opelka | 40 | 6 | ||
 Serbia | Miomir Kecmanović | 42 | 7 | |
 Kazakhstan | Alexander Bublik | 45 | 8 | |
| Tennys Sandgren | 50 | 9 | ||
| Sam Querrey | 51 | 10 | ||
 Australia | Jordan Thompson | 52 | 11 | |
| Serbia | Laslo Đere | 56 | 12 | |
| Aljaž Bedene | 58 | 13 | ||
 Spain | Pablo Andújar | 59 | 14 | |
 Canada | ||||
| Spain | Feliciano López | 63 | 16 |
The following players received wildcards into the main draw:
The following players have been accepted directly into the main draw using a protected or a special ranking:
The following players received entry as an alternate:
Damir Džumhur → replaced by Matthew Ebden
Kyle Edmund → replaced by Gianluca Mager
Yasutaka Uchiyama
John Isner → replaced by Andreas Seppi
Ilya Ivashka → replaced by 
Nam Ji-sung Steve Johnson → replaced by Kamil Majchrzak Vasek Pospisil → replaced by Thomas FancuttThe following pairs received wildcards into the doubles main draw:
The following pairs received entry as alternates into the doubles main draw:
Oliver Marach → replaced by Scott Puodziunas / Calum Puttergill Steve Johnson / Sam Querrey → replaced by Roberto Carballés Baena / Pablo Cuevas Reilly Opelka / Vasek Pospisil → replaced by Tristan Schoolkate / Dane SweenySee main article: 2021 Great Ocean Road Open – Singles.
Jannik Sinner def. Stefano Travaglia, 7–6(7–4), 6–4See main article: 2021 Great Ocean Road Open – Doubles.
Jamie Murray / 
Bruno Soares def. 
Juan Sebastián Cabal / Robert Farah, 6–3, 7–6(9–7)
Slovakia
France
Finland
New Zealand