The 73-year-old owner clinched his fourth Melbourne Cup last year on the back of the Robert Hickmott-trained Green Moon but his hunger for Australia's richest and most famous thoroughbred trophy shows little sign of abating.
Green Moon, who defied 22-1 odds and a field of quality European stayers to win the gruelling two-mile handicap, returns to Flemington Racecourse to bid for back-to-back Cups, but the seven-year-old stallion is among the less fancied of Williams' sextet.
Sea Moon, Fawkner and Seville are all highly backed to win, with Masked Marvel and Mourayan rated rough chances to salute in front of an expected crowd of more than 100,000.
With all prepared by Williams' trusted trainer Hickmott and only Mourayan drawing outside barrier 10, the tycoon's powerful bid has proved controversial, with English trainer Ed Dunlop raising concerns that the race could be manipulated.
"I hope Mr. Williams isn't allowed to boss this race," Dunlop, who has entered eight-year-old gelding Red Cadeaux for a third tilt, told local media.
"It is not ideal, let's not beat about the bush. We are drawn wide. I think the most interesting thing is Lloyd Williams' horses are all very well drawn."
The reclusive Williams hit back at Dunlop's 'team orders' comments on Monday, describing them as "extremely poor manners".
"Twelve months ago this Friday, I put plans in place for eight horses to be aimed at the Melbourne Cup and six have made it," Williams, known for his meticulous management of his horses, told The Australian newspaper.
"Racing is like business, you have got to have a plan."
Dunlop's comments have touched a raw nerve with Australia's racing community, which has bemoaned the rising strength of foreign-prepared entrants and happily adopted a siege mentality hyped up by local media.
Australian racing has also been hit by a string of corruption scandals in recent years and last year's race was tarnished when stewards allowed jockey and former winner Damien Oliver to ride despite being embroiled in an illegal betting probe.
Having served a 10-month ban for placing a bet on a rival horse, Oliver returns to ride on the Gai Waterhouse-trained Fiorente which most agencies had installed as a 7-1 favourite on the eve of the race.
Runnerup last year, Fiorente was Waterhouse's third second-placing after Te Akau Nick in 1993 and Nothin Leica Dane in 1995.
"It's probably made me keener and hungrier than ever," Oliver said of his ban, which pundits criticised as lightweight for not precluding him from Australia's richest spring racing season.
"I'm very keen to reward Gai and hopefully share in her first Melbourne Cup."
Of the nine foreign-prepared entrants, Mount Athos is rated the strongest chance to win and give trainer Luca Cumani a maiden Melbourne Cup after runnerup finishes with Purple Moon in 2007 and Bauer the following year.
The powerful Godolphin stable, also chasing a first Cup triumph after 15 fruitless years, has entered a single challenger in Saeed Bin Suroor-trained Royal Empire, a five-year stallion to be ridden by former winner Kerrin McEvoy.
Former England striker Michael Owen has also flown to Melbourne as part-owner of the Tom Dascombe-trained Brown Panther.
Australia's holy grail of racing has never fallen into English hands, and Owen was guarded about the chances of the six-year-old stallion breaking the drought.
"To be the first would be a huge honour. (But) we're not getting too carried away," he said.