A six-time stage winner at the Tour de France, Alaphilippe won back-to-back men's world road race crowns in 2020 and 2021 but has been plagued by injuries since.
"I am very happy to be returning to Australia," said the 31-year-old Alaphilippe, who previously raced the event in 2014 on his professional debut.
The Tour Down Under for men and women will take place in and around Adelaide next month, with the men's race from January 16-21, featuring the brutal Willunga Hill climb twice and finishing on an ascent to Mount Lofty.
"There are many undulating roads and tough climbs throughout various stages of this race.
"I'm particularly excited to revisit Willunga Hill along with Mount Lofty for the first time," added Alaphilippe, who will be one of the favourites for the race leader's ochre jersey.
The Soudal Quick-Step rider is a one-day race specialist, but he has won two stage races - the 2016 Tour of California and the 2018 Tour of Britain.
He came close to winning the Tour de France in 2019, losing the yellow jersey with just three days to go.
Race director Stuart O'Grady said of the Frenchman: "He is a true champion of our sport, and a born entertainer on a bike. We can't wait for him to race in Australia's greatest cycling race."
Alaphilippe is on the comeback trail after suffering broken ribs and a collapsed lung in a high-speed crash in April 2022 and then injuring his knee in a tumble at the Tour of Flanders in March this year.
The women's Tour Down Under takes place from January 12 to 16.
