The Northern Irish defender, 24, has made 141 appearances for United, scoring four goals since his debut against Coventry City in the League Cup, in September 2007.
Sir Alex Ferguson said: “Jonny has risen through the ranks to become an integral part of the first team squad. He has developed into a top player for us and has scored a couple of important goals this season too. I am delighted he has signed a new contract.”
Jonny Evans said: “I’m delighted to sign my new contract. I am so proud to play for such a great club, and there’s no better feeling than playing football in this team and winning games.
“I have always felt that this is the right club for me. Even when I was 9 or 10 years old back home in Northern Ireland, clubs asked me to go on trial but I didn’t go because I knew that Manchester United was the place I wanted to play football. I have come through the Academy here and developed as a player with the help of all my team-mates, the manager and the coaching staff. I would love to play here throughout the rest of my career.”