Owen will join United on a free transfer after his contract at Newcastle United expired at the end of June.
Manager Sir Alex Ferguson told the club’s official website: “Michael is a world class forward with a proven goalscoring record at the highest level and that has never been in question.
“Coming to Manchester United with the expectations that we have is something that Michael will relish.”
Owen said: “I had just begun to talk to other clubs when out of the blue Sir Alex phoned me on Wednesday afternoon, invited me to have breakfast with him the next morning during which he told me that he wanted to sign me. I agreed without a moment’s thought.
“This is a fantastic opportunity for me and I intend to seize it with both hands.
“I am now looking forward to being a Manchester United player and I am fortunate that I already know so many of the players here. I missed pre-season last year and am pleased that I will be starting at Carrington from day one.
“I want to thank Sir Alex for the faith he has shown in me and I give him my assurance that I will repay him with my goals and performances.”