Adelaide-born actor Damon Herriman plays notorious cult leader Charles Manson in Quentin Tarantino's upcoming ninth film Once Upon A Time In Hollywood.

And speaking on Channel Nine's Today Extra on Tuesday, the 48-year-old revealed what it was like working with the legendary director.

'I'd heard that it's the most fun that you'll ever have from a couple of other actor friends, and I have to say it was,' he said.

'He's certainly one of the hardest roles I've ever played': Damon Herriman has revealed what it was like portraying killer cult leader Charles Manson in Quentin Tarantino's new movie

'He plays music between shots and every hundred rolls of film they'll celebrate with a table of booze. It's very unlike any other on-set situation I've experienced before.'

Damon is best known for this roles in Australian TV shows All Saints and Love My Way, and films including The Water Diviner.

Once Upon A Time In Hollywood is about a faded TV actor and his stunt double who try to break into the film industry during Manson's reign of terror in the late '60s.

Major players: Once Upon A Time In Hollywood star Leonardo DiCaprio (left) and the film's director Quentin Tarantino (right) are pictured in Las Vegas on April 23, 2018

Margot Robbie plays Sharon Tate, Leonardo DiCaprio takes on the role of actor Rick Dalton and Brad Pitt plays his stunt double Cliff Booth.

'The dialogue is so great,' Damon said. 'It's set in 1969, so the design is amazing.'

Damon also revealed how challenging it was to play cult leader Manson, saying: 'He's certainly one of the hardest roles I've ever played as he's not just one thing.

Tension in tinsel town: Once Upon A Time In Hollywood is about a faded TV actor and his stunt double who try to break into the film industry during Charles Manson's reign of terror in 1969. Pictured: Charles Manson

'Depending on the mood he was in on a particular day he did an interview, or who he happened to be talking to or the way they were talking to him, he would present as a very different guy.

'And within the same interview he could change on a dime as well. Working out which version of Charlie Manson you're playing was one of the hardest parts.'

The veteran actor added that he 'read and watched everything I could get my hands on' about Manson in preparation for the role.

A-list cast: Damon stars alongside Brad Pitt (left) and Australia's own Margot Robbie (right)

'I just read and watched everything I could get my hands on. It's intimidating playing a real person, anyway, certainly someone as well-known as him,' he explained.

'It's particularly intimidating as you want to get it right.'

Once Upon A Time In Hollywood is set for a cinema release in 2019