Pellegrini took over the London Stadium reins in 2018, replacing David Moyes after the Scotsman had successfully led the club away from an unnerving relegation battle.
The Chilean became the clubs fourth manager in three years when he took charge, but his position looks to be secure as the club look to push on towards European qualification.
Noble, who continues to marshal the troops in midfield, has now revealed that Pellegrinis personality has been a key ingredient in helping the Hammers improve.
Speaking to Radio 5 Live, he said: "I think his personality is just so calm. Theres no antics with him, you dont hear anything. He doesnt want the limelight. He doesnt do many interviews but he works with us every single day on how to improve as a club."
The 32-year-old continued by insisting that the former Manchester City boss is changing the mentality of the club for the better. He revealed: "The mentality of the football club is changing slowly and I can feel it.
"I mean, the way we started last year was terrible. To only be five points off the Europa League spot - I think hes slowly but surely changing the club."
Noble rounded off by insisting that as a result of his personality and preferred playing style, he expects Pellegrini to have a long future at the club.
"I think hes going to be here for many years, I really do. I think his personality and the way the fans have taken to him and the way we play football - I really do think hell be here for years."
The Hammers face Manchester United on Sunday, where theyll look to catapult into the top six with victory over the Red Devils for the second successive season.