The men’s six-stage event is preceded by the three-stage women’s tour, starting in Adelaide on Friday.
That race features last year’s Olympic team pursuit gold medallist Chloe Dygert and reigning Tour de France queen of the mountain Justine Ghekiere.
Welshman Williams stormed to victory at Mount Lofty in the 2024 showdown, powering past his rivals in the final few hundred metres to hold on to the ochre jersey and top spot.
It helped launch him into a successful season with victory at the Tour of Britain in September and a four-year contract extension with his powerful Israel-Premier team.
“Winning my first Tour Down Under was an unbelievable moment for me,” Williams said ahead of the men’s race from January 21-26.
“It put into motion a terrific year for me. I’m chasing another strong result to kickstart my 2025 season, and hopefully it will lead to another breakthrough year.”
Israel-Premier are expected to be challenged in Adelaide by the UAE-Team Emirates line-up featuring 2023 TDU winner Vine and former INEOS Grenadiers rider Jhonatan Narvaez, who was the runner-up behind Williams last year.
“I’m really looking forward to the race,” Vine said.
“I had a really good summer of preparation in Australia and am excited to be in Adelaide for the Tour Down Under, a place where I have some amazing memories.
“We have a really strong team for the race and are aiming for some big results.”
Vine has bounced back from a horrific crash in last year’s Tour of the Basque Country in April when he suffered spinal injuries. His neck was placed in a brace and he feared he would never walk again.
He recovered to win the king of the mountains classification at the Vuelta a Espana last September, before claiming gold for Australia in the UCI Road World Championships in the mixed team relay.
Welshman Thomas, who will be competing in his 10th Tour Down Under for INEOS Grenadiers, said: “For me, it’s the best place to start, you have a month or five weeks in Australia with consistent training and good weather — it’s ideal.”
The women’s peloton also includes Ruby Roseman-Gannon (Liv-Alula-Jayco), Chloe Dygert (Canyon-Sram), Amanda Spratt (Lidl-Trek), and Olympic silver medallist Ally Wollaston (FDJ-Suez).
Ghekiere, who also won the mountains classification in last year’s Giro d’Italia, is part of the AG Insurance-Soudal line-up.
Last year’s winner Sarah Gigante will not compete after undergoing surgery for a vascular condition.
© 2025 AFP