Evra, 27, still had another year to run on his previous deal but Sir Alex Ferguson wanted to reward him for an impressive season and the left-back is now due to stay at Old Trafford until 2012.
"The last two-and-a-half seasons have been the start of a dream for me," Evra said. "It is a pleasure and an honour to be part of this fantastic side and to be coached by Sir Alex Ferguson and his staff.
"Manchester United is more than a club, it is a family I am proud to be a part of and that is why it has always been a first choice for me. I declared when I arrived that I was coming here not just to play but to win and United is the ideal place to realise such a dream.
"It is a privilege to play in front of our fantastic fans and I am sure that the success we have earned in the last two seasons confirms the history of this club and will be the start of something even more special."