The school will receive professional guidance from a landscape architect and the winner will receive a park makeover worth up to $10,000.
Highgate had more than 870 votes for its entry, which was a video that looked at how they could use limited space efficiently in the school.
Australian Institute of Landscape Architects chief executive Shahana McKenzie said the initiative was more than transforming space in one school.
“It’s about getting schools and communities in Australia to rally together and seriously consider the importance of well-designed outdoor spaces for their wellbeing, today and in the future,” Ms Shahana said.
Almost 100 schools across Australia entered the competition.
The winner will be announced on May 1.