Cycling's rock star has not raced the TDU since the start of his road racing career in 2010 at the age of 19, preferring to start his season a little later and closer to home in preparation for the Spring Classics.
Sagan's early season start in Australia was no doubt further cemented by the recent promotion to WorldTour status of the Cadel Evans Great Ocean Road Race, held immediately after the TDU.
The Slovakian currently leads the WorldTour rankings and brings to his new team Bora-hansgrohe (currently Bora-Argon) a raft of WorldTour points almost ensuring the team's own promotion to WorldTour status.
However, Sagan and his team's participation at the Tour Down Under is solely dependent on the confirmation of its WorldTour licence, not expected until late November.
"The Santos Tour Down Under holds a special place in my heart," Sagan said in a statement to The Advertiser.
"Returning after seven years to the race that set off my professional career is a great feeling and I look forward to riding on the roads of Adelaide and South Australia."
South Australia Sports Minister Leon Bignell said Sagan's attendance is a coup for the event and will be guest of honour at the Legends dinner following the iconic Willunga Hill stage.
"The race and the fans are in store for something special next year when he tackles (Willunga) for the second time," race director Mike Turtur said.