25 May 2015 Last updated at 08:01 BST
Students aged from nine to 12 have been asked to create their designs in the blocky 3D world.
The results could then be made to existing national parks around Adelaide.
The government has set aside nearly $10.4m Australian dollars (Â£5.4m) for the redesigns.
It's all part of a government plan to make the most of kids' creativity.
The only rule is that "whatever you design needs to be able to be created in the real world," said the website which announced the prize.
"The park features need to complement the natural environment, taking into account the animals and plants that live there."
"Ideas could include trails for bushwalking, mountain biking or horse riding, barbecue and picnic areas - or something completely different," it suggested.
A news team in south Australia popped in to a school that's taking part to see some of their cool ideas.
Thanks to Carl from ABC's 'Behind the News' programme in Australia who sent us this report.
Kids in Australia are getting involved in a competition to design a national park in Minecraft which could then be built in reality.