Several United players expressed delight on their Twitter accounts on Monday afternoon after hearing about their new team-mate.
said: "Welcome to Man Utd Phil Jones. Looking forward to playing with u," while defender
said: "Welcome to Phil Jones. Another top young talent joining the club. The future is bright."
Blackburn boss Steve Kean revealed the club had made a "staggering" offer in an attempt to keep hold of their star defender.
"Phil wants to play Champions League football now and we're not at that level," Kean said.
"I'm sure we will be in the coming years, and we gave it a real good try and made him a fantastic offer, but I understand why he wants to go now.
"He goes with our blessing and it's an opportunity for us to invest in other young players across other areas of the pitch.
"We were hoping he was going to be captain of our club and captain of England, he's a fantastic prospect and I'm sure he'll be an England regular very soon."
The teenager will face a battle to immediately break into United's first team with Ferdinand and Nemanja Vidic the clear first choice for the centre-half spots.
Chris Smalling and Jonny Evans are also competing for places at the heart of Sir Alex Ferguson's defence.
A string of fine performances by Jones helped Blackburn end their season with a four-game unbeaten run, which included a 1-1 draw with United and wins over Bolton and Wolves, to guide them to Premier League survival.
Preston-born Jones joined Blackburn's youth set-up in 2002, making his debut in a Carling Cup win at Nottingham Forest in September 2009. His first Premier League appearance came six months later in a 1-1 draw with Chelsea at Ewood Park.
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