Philip, 36, retired from playing football after leaving Everton at the end of last season. He played for Manchester United from 1995 to 2005 and is currently taking his coaching badges.
Announcing the appointment, manager David Moyes said:
"I have known and worked with Philip for eight years and, in that time, I have come to know his dedication, ability to lead and appetite for hard work. In addition, of course, he understands the club very well and I think his addition to the coaching staff will be a valuable one."
Philip Neville said:
"When I retired from football, I knew that I wanted to continue in the game; it’s something that I have been preparing for over the last few years. So when David called to give me this opportunity, I couldn’t resist. I gave my all when I played for Everton but it is no secret that this club is in my heart. I’ve really enjoyed working with David and his staff as a player and I think that, together with Ryan, we can make a real contribution to Manchester United."