The former Red Devils star, who made 455 appearances for the club, believes the Portuguese has improved things since taking charge.
Ferdinand won six Premier League titles under Sir Alex Ferguson, and moved to QPR the season van Gaal took charge.
The Dutchman led United to a fourth place finish in his first season, before guiding the Manchester club to fifth and FA Cup glory in his second.
But despite winning silverware, van Gaal was heavily criticised for his style of play and was subsequently sacked.
Mourinho took over and, despite finishing sixth, led the Old Trafford side to Europa League and League Cup glory.
Asked for his evaluation on Mourinho’s first season, Ferdinand said: “For what he was asked to do you got to say he was a success.
“But finishing sixth, when you look at it like that, and you didn’t have all the other stuff, you would say it would be a disappointing season.
“I think this is a season where he gets a little bit of respite and it’s time to continue and build.
“I definitely think there’s been an improvement in the way the team’s played. The idea of going to Old Trafford isn’t boring like it was for the last couple of years.
“I didn’t enjoy watching Manchester United the last couple of years. This season has been better, so you hope that will continue.”