Alex Marquez will make the step up to MotoGP for the 2020 season and join brother Marc Marquez at Repsol Honda.
Alex, 23, won the Moto2 title in 2019 and is now to follow in the footsteps of reigning MotoGP champion Marc.
Marc claimed the Moto2 championship in 2012, before topping the riders' standings in six of his seven seasons in the premier class.
Honda have signed Alex to replace three-time MotoGP champion Jorge Lorenzo, who retired at the end of the season.
Alex has signed a one-year contract with the team as he prepares to ride the Honda RC213V in his debut campaign in the top category.