The 34 year-old will join the channel from August 2013 on a three-year deal as an interviewer, programme maker and football expert, building on his media experience gained at his #5 magazine.
The centre-back, recently named in the Professional Footballers' Association Team of the Year, will also appear in advertising campaigns promoting the channel, which will have no impact on his playing career at Old Trafford.
He told the media: “I’m really excited about joining BT Sport. I will be doing a lot more than sitting on a sofa working as a football expert. I am going to be able to make programmes for BT Sport, not just about football, but also about other things that I am passionate about.
"And I will also be continuing to turn the tables as an interviewer putting the questions to big name stars, rather than answering the questions, like I do with my interviews for #5 magazine.”
The new channel will broadcast 38 Premier League fixtures next season as well as top-flight games from Italy, France, Brazil and USA.
BT's acquisition of ESPN's UK and Ireland TV channel's business means that it will have the rights to show live games for the FA Cup, Scottish Premier League, Europa League and the German Bundesliga.