Australia's quirkiest race is ready to return after a four year hiatus

The Australian Dunny Derby returns to the heart of Outback Queensland this month, with Winton's Outback Festival, which will run from Tuesday, September 19 to Saturday, September 23.

Winton is preparing to host predicted record crowds since the Outback Festival first started in 1972.

Grey nomads, families and athletes will roll into town for the 27th anniversary of the festival - two years in the making - to celebrate all things Aussie outback with a 5-day jampacked program and no shortage of activities for everyone.

The race is on to claim the golden porcelain throne in the iconic Dunny Derby, which will see competitors get down to business.

20 outhouses on wheels are set to lineup at the starting blocks to race the 200-metre course of obstacles vying for the golden throne and a flush of cash.

Festival Co-ordinator, Robyn Stephens, said it was great to see the excitement across Winton start to build in preparation to roll out the welcome mat, especially for the "hilarious" Dunny Derby.

"We've got festival-goers from every state of Australia who have been eagerly waiting to whip out to Winton for the festival, and this is predicted to be our biggest yet, swelling the town's population by more than 5 times the size," she said.

"We're looking forward to seeing the competitive and outback spirit ignite this September from our sold out True Blue Aussie Sports competition, to the thrones of racing outback outhouses to our gruelling 5-day Outback Iron Man and Woman Challenge with a distinctly Outback twist."

Day one of the festival will see the week-long Outback Iron Man and Woman challenges begin, where competitors will put not only their physical, but also mental strength to the test, battling it out over a series of gruelling events.

And even more competitors will challenge themselves in the Western River Run and Outback Century Cycle Challenge.

The less serious competitors will take on the full-day True Blue Aussie Sports Competition across the town's watering holes, including pool, bowls, cow pat discus and the Troo Bloo Roo Poo final.

Little Swaggies events and Outback Iron Juniors challenge will run throughout the week, alongside Whip Cracking Championships, Swag Throwing, Wool Bale Rolling and Bushman's Egg Throwing.

There will be Bush Poet's Breakfasts in the morning, Sunset Gala Charity Dinner in the evening - partnership with the Royal Flying Doctors Service - and the Grand Festival Parade.

This year's festival features a bumper lineup of live music, including rock legends Dragon headlining the Dunny Derby Concert on Friday, September 22, alongside country artist Ben Ransom.

For fans of the 'Man in Black', the Johnny Cash Special Show is not one to miss on the festival's opening night, with some of the greatest hits of this iconic artist to be played.

There will be plenty of free performances throughout the week, with multi-Golden Guitar winner Kirsty Lee Akers, Wade Forster, Matt Angell and Tim Griffin all set to hit the stage.

The Australian Eagles will close the festival at the Festival Finale and Fireworks Spectaular on Saturday, September 23.

"There really is no better way to see Outback Queensland than with a road trip to celebrate Winton's famous Outback Festival," said Ms Stephens.

Last minute festival camping, passes and tickets on sale: outbackfestival.com.au