The Belgian global has entered a fresh deal that will keep him at Old Trafford until 2020, with the option of a further year. Since joining the club, he has won the FA Cup, Community Shield, Europa League and League Cup.
Fans of the Red Devils though are not pleased with announcement as Andrew Southwick described it as "the worst news" related to Manchester United he has seen in a long time.
Fellaini started five of United's 38 Premier League games last season and made a total of 23 appearances across all competitions, scoring five goals.
Eamon Dunphy couldn't hide his love for Marouane Fellaini after the Belgium midfielder's performance on Thursday night. "Also, I feel like this team, under José, still has a lot we want to achieve", Fellaini told the club's website.
The Belgian midfielder, who featured in Thursday night's win over England in the ongoing World Cup in Russian Federation, thanked Manchester United manager Jose Mourinho "for the faith he has" in him.
However, Express Sport understands Fellaini's options dried up and he was left with no choice but to thrash out terms with United instead.
"I am very happy Marouane is staying with us", he said.
"My focus now is on the World Cup but I am looking forward to a successful season ahead".