The attacking midfielder moves to Old Trafford for a British transfer record and cannot wait to link up with manager Louis van Gaal and help return the Red Devils to the top
The Argentine has penned a five-year deal and joins Louis van Gaal's side following four seasons at the Santiago Bernabeu, culminating in a Champions League win last year.
He is excited to be moving to United, claiming that only they made leaving Carlo Ancelotti's side an appetising prospect.
"I am absolutely delighted to be joining Manchester United," he told the club's official website. "I have thoroughly enjoyed my time in Spain and there were a lot of clubs interested in me but United is the only club that I would have left Real Madrid for.
"Louis van Gaal is a fantastic coach with a proven track record of success and I am impressed by the vision and determination everyone has to get this club back to the top – where it belongs. I now just cannot wait to get started."
Di Maria will be available for the club's trip to Burnley on Saturday.