"Paris Saint-Germain is delighted to announce the signing of Angel di Maria until June 30, 2019," read a club statement.
Di Maria, 27, had already passed a medical in Doha before flying to Paris on Wednesday after Qatar-owned PSG had agreed a fee of 63 million euros with United.
That makes Di Maria the second most expensive player in the history of French football behind Uruguayan striker Edinson Cavani, who joined Paris from Napoli for 64 million euros in the summer of 2013.
"I want to win the Champions League, which is a dream for all footballers, for a second time. We will do everything we can to bring Europe's biggest trophy to France and the fans of Paris Saint-Germain."
The former Rosario Central, Benfica and Madrid star will be looking to recover his very best form after a disappointing season in the Premier League with United.
He is the third major summer signing for Laurent Blanc's side after German goalkeeper Kevin Trapp joined from Eintracht Frankfurt for 9.5 million euros and midfielder Benjamin Stambouli penned a five-year deal after moving from Tottenham Hotspur for nine million euros.
The arrival of Di Maria could be bad news for his compatriots Javier Pastore and Ezequiel Lavezzi and Brazilian winger Lucas, who all now risk being pushed down the pecking order at the Parc des Princes.
