Williams and Hall confirmed the fight on Thursday, pitting the 36-year-old former All Blacks and Roosters star against the 44-year-old Sydney Swans icon.
Hall went down in AFL infamy for knocking out a rival player with a sickening punch in 2008, and fought out a draw with league star-turned-boxer Paul Gallen in 2019.
Williams said his return to the ring was to scratch his last sporting itch, and will soon depart north to work with Parker and Fury as he tries to finish his sporting career with a successful chapter in the fight game.
“I’ve stated this before that I want to have five to 10 fights,” Williams said. “But, in order for that to come to fruition I need to beat Barry.
“No stone will be left unturned in this journey. Starting with tonight I’m flying out to the UK. I'm flying out to the UK. I’ve been invited by Joe Parker and Tyson Fury to do some training with him over there.
“When that opportunity arose I couldn’t say no, just to learn from the best. It shows my commitment to this sport, and this fight.
“He [Fury] is the best way in the world at the moment. the best fighter of our generation, and being able to rub shoulders with him...just to see his mentality.”
Williams has had a sporadic boxing career, often going long periods without a fight, as he tried to squeeze in fights between his rugby and league commitments.
Williams’ last bout was in June last year, when he beat Waikato Falefehi in a 57-56 unanimous-points victory at Townsville Entertainment Centre.
However, the victory was far from convincing and Williams had to survive a knockdown scare, being put on the canvas on an eight-count in the second round of the fight.
That fight highlighted his lack of time in the ring, but Williams – who will also promote the Hall fight through his new company, SBW Promotions – said that a sense of unfinished business had brought him back into boxing.
“It's about the challenge,” Williams said. “I said to my family, ‘I want to give boxing one more crack to scratch that itch’.”
“I haven't fought for seven years, but I’ve been there or thereabouts. When we get in that ring, yes I respect Barry as a fighter and man but I intend to win, by any means necessary. I feel that mentality is going to get me a good win.”
The father of four will leave wife Alana and the children behind to focus on his UK training camp, a move Williams was prepared to make despite the disruption to his family life.