The Red Devils clinched their 20th top flight title courtesy of a 3-0 win over Aston Villa at Old Trafford on Monday night, with Robin van Persie netting a hat-trick, and Rooney felt it was a championship thoroughly earned by the great club.
"It's what we worked all year for and we've fully deserved it," Rooney told Sky Sports. "We won this game in the first half and it is a fantastic night for us.
"When you lose the title (last season to Manchester City), it's hard to take and the way we did it wasn't a nice feeling last time so we've all dug in deep and all worked together and done fantastic to put ourselves in the position tonight to finish the job off.
"You know how football is so you never take anything for granted so we worked hard and thankfully now it's done.
"The manager has great desire and a winning mentality. We all buy into that and want to do well for the club."