Giro d'Italia champion, Richard Carapaz will join Team Ineos from the start of the 2020 season.
The 26-year-old Ecuadorian has agreed a three-year deal with the team and adds to an already impressive stable of riders that includes Tour de France champions Chris Froome, Geraint Thomas and Egan Bernal.
Team principal Sir Dave Brailsford - whose team have won seven of the last eight Tour de France titles - said: "He is obviously a fantastic climber but also has great versatility as he showed at the Giro earlier this year.
"He is still relatively young and I have no doubt he can develop and improve even further at Team Ineos."
Carapaz became the first rider from Ecuador to win a Grand Tour when he triumphed at the Giro earlier this year.
He said: "I am very excited about joining the team. I feel this is a great opportunity for me to continue my development and growth as a rider, working with a team that continues to go from strength to strength, year after year.
"I believe I will fit into this group well and race to my full potential over the coming years. I want to achieve some great triumphs for Team Ineos."
Meanwhile, two-time grand tour champion Nairo Quintana is joining Arkea-Samsic on a three-year deal.
The 29-year-old Colombian, who won the Giro d'Italia in 2014 and the Vuelta in 2016, has also twice finished runner-up at the Tour de France.