Sir Alex Ferguson's side usurp Liverpool as the most successful side in English football.
United clinch record title triumph
United needed just a point from this game to regain the title from Chelsea and they got it when England striker Wayne Rooney scored from the penalty spot 17 minutes from time after Blackburn goalkeeper Paul Robinson brought down Javier Hernandez.
Australia's Brett Emerton had fired Rovers, still not certain of top-flight survival, into a 20th minute lead before Rooney settled United's nerves with a powerful spot-kick.
The result gave United, now in sole possession of a record they had shared with arch-rivals Liverpool, an unassailable seven-point lead at the top of the English Premier League table as closest pursuers Chelsea have just two matches to play.
"I was terrified, the ref took a long time to give it," Rooney told Sky Sports in relation to the penalty. "I had to compose myself, I'd been practising all week."
Rooney, who earlier in the season stunned United by handing in a transfer request, added: "After the year I've had, with the ups and downs, this is for the fans and the team."
United's latest triumph gave both manager Sir Alex Ferguson and Ryan Giggs a 12th English title. "It's a tough league to win and it's still as special as ever," Giggs said.
Asked about suggestions criticism the current team was not as good as previous United sides: "We're champions and in the Champions League. We're rubbish aren't we? "Twenty years ago we were nowhere near Liverpool. It's great credit to the club, the manager and the players and it's a good feeling to be ahead of our greatest rivals."