Melbourne Cup: Billionaire set to steal the show

He's bonafide racing royalty - and Sheikh Mohammed bin Rashid Al Maktoum has never been better placed to add a Melbourne Cup to his bulging trophy cabinet.

The Dubai ruler's Godolphin Stables has won more than 3500 races worldwide, including the world's richest race, the $10 million Dubai World Cup, on eight occasions.

But the race that stops a nation has so far eluded the 67-year-old. He has been runner-up on three occasions, including most recently Crime Scene in 2009.

This year promises to be different. Godolphin has five runners in today's race, including $5.50 race favourite Hartnell, ridden by champion Kiwi jockey James McDonald.

"He's the right horse to run really well in a Melbourne Cup," said McDonald, who has the ride on the John O'Shea-trained Hartnell and is the Sheikh's top rider.

"His form has been fantastic so there's no reason why he shouldn't be in the finish."

Oceanographer is the most highly-rated of the Sheikh's other runners - which include Geelong Cup winner Qewy and British horses Beautiful Romance and Secret Number.

More than 100,000 people are expected to come through the turnstiles at Flemington Racecourse for the $6.2 million race - the richest handicap race in the world and the biggest sporting prize in Australia which will be run for the 156th time.

The race will also welcome some of Australia's biggest celebrities to the exclusive Birdcage enclosure.

Elsa Pataky, Chris Hemsworth's wife and a successful actress and model in her own right, will be one of the biggest stars at the marquees. American entertainment personality Maria Menounos will also make her final Cup carnival appearance.

Australia's 2016 Eurovision entry Dami Im will perform the national anthem ahead of the big race at 3pm.

The Melbourne Cup is also one of the biggest for the fashion stakes, with bold looks and colours expected to take out fashions on the field. Unfortunately Melbourne's unpredictable weather shows no sign of letting up for the Cup, with a 50 per cent chance of rain expected during the big race.

- news.com.au with AAP