The Group 1 feature, the undisputed jewel in the crown of the month-long Deauville Festival, has been staged over the Normandy track's straight 1600m since 1921.
Dettori has a record seven Marois wins to his name, and the 52-year-old showman on and off the saddle returns on last year's heroine Inspiral in what promises to be an explosive edition.
Among those out to put a dampener on Dettori's farewell to a race he first won in 1999 are Light Infantry, beaten only a neck into second 12 months ago, and Triple Time. Neil Callan's mount edged out Inspiral when springing a 33-1 surprise in Royal Ascot's G1 Queen Anne Stakes (1600m).
Inspiral's connections were delighted however with that bold seasonal bow for their high-class filly, who was seriously compromised by Goodwood's soft going next time out when last of five to Paddington in the G1 Sussex Stakes (1600m).
With better ground predicted on Sunday the John Gosden and son Thady-trained runner has a great chance of triggering one of Dettori's famous post-win flying dismounts.
"She just didn't act on the ground at Goodwood. Frankie accepted it pretty quickly and she's only had two runs this year, so fingers crossed," Chris Richardson, racing manager to her owner-breeders Cheveley Park Stud, said.
Triple Time's trainer Kevin Ryan also saddles 2000 Guineas runner-up Hi Royal (William Buick).
Fierce French resistance awaits the English raiders led by last year's Marois third Erevann.
This is only his third run of 2023 after the Aga Khan-owned colt missed his warm-up due to a minor injury. Jockey Christophe Soumillon however reported his charge in sparkling form after a work-out at the track this week.
"He never shows much in the mornings but he's really well physically and is in ideal shape for the big race," Soumillon reported.
Big Rock runs for trainer Christopher Head whose father Freddy won this six times as a jockey and three as a trainer.
Big Rock is dropping back in distance after putting up a gallant bid to make all in the G1 French Derby (2100m), succumbing to Ace Impact in the shadow of the post (with Marhaba Ya Sanafi two-and-a-half lengths adrift in third).
In a high-class renewal Good Guess will have plenty of supporters.
Out of luck in the G1 French 2000 Guineas (1600m) won by Marhaba Ya Sanafi he earned his place in the line-up with a career-best performance to land the G1 Prix Jean Prat (1400m) at the track five weeks ago.
Master French trainer Andre Fabre has a record-equalling seven Marois trophies on his sideboard. He is represented this year by the relatively unexposed four-year-old Life In Motion, who registered a career-best performance when second in the G1 Prix Rothschild over course and distance a fortnight ago.
Fabre is double handed in one of the main supporting races on the card, the G3 Prix Gontaut-Biron Hong Kong Jockey Club (2000m), and will have high hopes for Group 1-winning filly Place du Carrousel.
