The club announced the appointment of the new Manager, ending the wait for who will replace Erik ten Hag, who was sacked.
Amorim, a Portuguese and two time winner of Primeira Liga titles with Sporting Lisbon, will join the club on November 11, 2024.
He has signed a deal until 2027.
The club said on its website: “Manchester United is delighted to announce the appointment of Ruben Amorim as head coach of the men’s first team, subject to work visa requirements.
“He will join until June 2027 with a club option of an additional year, once he has fulfilled his obligations to his current club.
“He will join Manchester United on Monday 11 November.
“Ruben is one of the most exciting and highly rated young coaches in European football. Highly decorated as both a player and coach, his titles include winning the Primeira Liga twice in Portugal with Sporting CP; the first of which was the club’s first title in 19 years.
“Ruud van Nistelrooy will continue to take charge of the team until Ruben joins.”