Mount had been no.19 at former club Chelsea.
Mason Mount's new squad number was revealed by Manchester United shortly after he signed from Chelsea. Mount has taken Cristiano Ronaldo's old no.7 jersey.
Chelsea's Mason Mount agrees personal terms with Manchester United
Mason Mount given iconic No 7 shirt at Man United following £60m transfer
WATCH: New £60m Manchester United man Mason Mount riles Chelsea fans as he and his dad label Old Trafford dressing room 'home' and 'special' days after leaving boyhood club
Mason Mount in line for first Manchester United appearance in Leeds United friendly - The Athletic
Mason Mount says he's had 'a very good start' at Manchester United and loves No. 7 pressure
Mason Mount discusses how Cristiano Ronaldo and other Man United no.7s 'inspired' him
Mason Mount shirt number: Why Man Utd signing was given number seven, Football
Man United officially unveil Mason Mount as first summer signing
Revealed: How much Mason Mount will earn at Man Utd as £60m transfer from Chelsea is finalised
Mason Mount has already given Alejandro Garnacho a Manchester United challenge - Richard Fay - Manchester Evening News
Mason Mount - Futbol on FanNation
New Mason Mount squad number revealed by Manchester United - Futbol on FanNation
Revealed: Erik ten Hag's stance on Mason Mount wearing the no.7 shirt at Man United - Football
Mason Mount - latest news, breaking stories and comment - Evening Standard