Marquez, who has spent his entire MotoGP career with Repsol Honda, winning six titles and 59 Grands Prix, lost faith in HRC’s ability to deliver competitive machinery after over 700 days without a race win.
The 30-year-old will now join younger brother Alex on year-old Desmosedicis at Gresini, having signed 'for the 2024 season' with the team rather than Ducati.
That will leave Marquez free to choose from a full range of potential factory destinations for 2025, when almost all existing rider contracts expire.
“I’m excited with this new challenge,” Marc Marquez said. “It wasn’t an easy decision because it’s a big change in every way. But sometimes in life it’s important to get out of the comfort zone and put yourself through the paces in order to keep growing.
“Bike-chance wise, I know I will have to adapt my riding style to a few things, and it won’t be easy. But I’m also sure that the whole Team Gresini will help me a lot. I can’t wait to get to know the team and start working with them. I’d like to thank Nadia, Carlo and Michele for the trust and respect they showed me.”
“This is a historical moment for the Gresini Family," added team owner Nadia Padovani Gresini. "The fact that Marc Marquez chose to race with us in the upcoming season is absolutely fantastic and I’m extremely happy to be able to make it official.
"In less than a season we got really close to his brother, and we’ll welcome Marc the same way, as we’re sure he has all the potential to be competitive on the GP23 from the get-go. Last but not least, I would like to thank Fabio Di Giannantonio for his professionalism, and we wish him all the best for the continuation of his career.”
The lack of factory machinery for Marquez could become a point for tension with Ducati, but both the Gresini and VR46 teams have won multiple races with year-old bikes.
After 14 victories with Honda from 2002-2006, Gresini became the factory Aprilia entry from 2015-2021 before enjoying instant success with Ducati and Enea Bastianini in 2022.
Bastianini won four races and finished third in last year’s world championship, propelling him into the factory Ducati team, with Alex Marquez arriving from LCR Honda as his replacement.
How much of a 'pathfinder' Alex might have been is unclear, but his instant jump in results won’t have gone unnoticed by Marc.
After finishing 17th overall for LCR, Alex took a pole and podium in only his second event at Gresini, then added a Sprint victory at Silverstone and, despite missing two rounds with rib injuries, is on course for his best MotoGP season.
Meanwhile, VR46’s Marco Bezzecchi has taken his GP22 to three Grand Prix wins and third in the world championship, underlining the potential of even year-old Ducati machinery.
While Marc Marquez’s first aim will be to secure his long-awaited 60th premier-class victory - assuming he doesn’t do so during his six remaining Honda appearances - he also has a chance to make history as the first satellite rider to win the MotoGP title.
Factory riders from Honda (Rossi, Hayden, Stoner and Marquez), Yamaha (Rossi, Lorenzo, Quartararo), Ducati (Stoner, Bagnaia) and Suzuki (Mir) have won all of the premier-class titles since 500cc was replaced by MotoGP four-strokes in 2002.
Sete Gibernau (2003, 2004), Marco Melandri (2005) and Franco Morbidelli (2020) have finished title runner-up while riding for satellite teams.
Gresini is the only satellite MotoGP team to have won races with more than one manufacturer.
Meanwhile, after spending huge amounts of money to sign multi-time champions Valentino Rossi (2011-2012) and Jorge Lorenzo (2017-2018), Ducati has now ended up securing the services of Marc Marquez for free.