"This has been the most difficult decision I have ever had to make,"
"But I am excited about joining Everton and relishing my next challenge in football.
"I've spent 18 years of my life at the club and I would like to thank Sir Alex, all the players and the fans for their great support during that time.
"This was a mutual decision between myself and the manager," Neville explained.
"I am now going to give the same commitment to Everton football club, David Moyes and the Everton fans. I can't wait for the new season to get started."
Sir Alex Ferguson said: "This was not a decision we wanted to make,"
"But every time I picked the team and Phil's name was not on the teamsheet, it was very difficult for me.
"You couldn't meet a better professional and he leaves with the gratitude of everyone at the club for his service to United.
"I wish all the best to Phil and his family,"
While his new boss David Moyes seems to be very pleased to have got him in his squad.
"We have staved off a great deal of competition to get him," he told Everton's website. "Several clubs were interested in signing him, but I must say from the first minute I spoke to him he only wanted to join Everton.
"His attitude throughout the entire negotiation process has been first-class.
"Primarily, I see Phil as a holding midfield player but he is so versatile that he gives us several additional options; he's comfortable playing in the holding role or at right or left back.
"He's a quality footballer who will, I feel certain, improve and enhance the squad we are putting together here at Everton. He is very much a professional's professional and I am very happy to have signed him."