Actor Cate Blanchett has thrown her support behind the Voice to Parliament, considering the upcoming referendum "an incredible opportunity" in Australia's history.

"It's an extraordinary time for an extraordinary country," Ms Blanchett told ABC's Sarah Ferguson.

Ms Blanchett made the comments whilst appearing on 7:30 alongside director Warwick Thornton, the pair promoting Thornton's upcoming release, The New Boy.

"We have this incredible opportunity to embrace our unique history, shared history, you know, with all of its missteps and all of its successes, to actually evolve into a really modern democracy, like New Zealand, like Canada," Ms Blanchett said.

The New Boy focuses on an Indigenous boy, played by 11-year-old Aswan Reid, who is captured by trackers before being taken to a remote South Australian monastery.

Mr Thornton said the plot was inspired by his lived experience after attending boarding school in Western Australia.

"As a child, I had never been into a church. And I was a bit of a ratbag on the streets of Alice Springs, and my mother went, 'Right, up to boarding school you go,'" Mr Thornton told 7.30.

Mr Thornton, who is best known for his 2009 release Samson and Delilah and 2017 western drama Sweet Country said his movies provide a "voice to the voiceless".

"Most films I do, it's about giving people, who are my people, my grandparents, my ancestors, and my grandchildren a voice that they've never had. And that's incredibly important for me," he said.

He also drew comparisons between his films and the Voice to Parliament debate.

"It's a strange time," he said.

"I feel that we're in a country that feels like a spoilt single child who'd only learned the word 'no' and one day needs to learn the word 'yes'."

Ms Blanchett said she hoped Australia would be able to reflect on the Voice to Parliament in future years in a similar fashion to equal voting rights.

"Change felt terrible. And the debate was all about, 'The society is going to collapse'," Ms Blanchett said in relation to women gaining the right to vote.

"Now, can we imagine a world in Australia where women didn't have the right to vote? Where their voices weren't heard? No, we can't.

"It's time we evolved to include all Australians … The more inclusive cultures are, the more vibrant they are.

"I'm hoping, in another 120 years' time, we'll look back at this moment and say, 'Can you believe we almost missed that opportunity?'"

The Voice to Parliament referendum is set to be held in the final quarter of this year.