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.
<sub>*per team</sub>
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:
The following pairs received wildcards into the doubles main draw:
The following pairs received entry as alternates into the doubles main draw: