Terms were agreed some weeks ago over the five-year deal and Ferdinand put pen to paper today to end all speculation over his future at Old Trafford.
"Rio's contribution this season has been a major factor in our outstanding defensive performance and I am delighted he has signed a new contract," said manager Sir Alex Ferguson.
Ferdinand has taken the skipper's armband on a regular basis with Ryan Giggs used so sparingly towards the back end of the campaign and is likely to lead United into their Champions League final meeting with Chelsea on May 21.
And though Gary Neville will be back from injury next season, the implication is as soon as the long-serving full-back stands aside, Ferdinand will get the job full-time.
"Rio has matured into his role at the club and has shown, when needed, what a great captain and leader he can be," said Ferguson.
Coming just before United head out to Moscow, aiming to become European Cup winners for the third time, the news offers Ferguson and his men the perfect lift.
It also avoids the kind of long-running saga which characterised Ferdinand's last contract talks.
At one stage, the defender was booed by his own supporters as they failed to understand why negotiations were taking so long.
This time however, talks have been conducted smoothly, leaving Ferdinand delighted.
"Manchester United is a fantastic club and I am delighted I have signed a new contract," said Ferdinand, who clinched his third Premier League title after beating Wigan on Sunday.
"It is a great honour to be part of this trophy-winning team and to share in the success, which I am sure will continue for many seasons to come.
"I would like to thank the manager, the coaching staff, the players and the fans for the tremendous support they have given me since I joined the club."