The Portuguese replaced Louis van Gaal, with the team's style of play under the Dutchman reportedly key to the decision to terminate his contract in May
Mourinho's brand of football has also provoked plenty of discussion
Here, Press Association Sport looks at what United might deliver on the pitch with the Portuguese at the helm
:: What do United want?
United are a club with a strong tradition of swashbuckling, attacking football and the fans enjoyed plenty of that during Sir Alex Ferguson's lengthy reign as boss
But it has been in far shorter supply since Ferguson's retirement in 2013 and, many would argue, was virtually non-existent in Van Gaal's second and final term in charge
United scored only 49 times in the Premier League in 2015-16, their worst return for 26 years, and at one point they went 11 successive home games in all competitions without registering a first-half goal
The craving for something more dynamic was clear from the cries of ''attack, attack, attack!'' frequently heard from the stands at Old Trafford, accompanied by fierce criticism from ex-players turned pundits
But generally a positive response was not forthcoming - and Van Gaal paid the price
:: What have we seen from Mourinho so far?
As his trophy-laden CV would suggest, more often than not Mourinho's teams get the results he wants, but he has faced accusations of achieving his aims with a negative approach
There are notable examples to support that, with defence apparently prioritised over attack in a number of big games
During the 2013-14 season, then Liverpool manager Brendan Rodgers said of Mourinho's Chelsea after the Blues' 2-0 win at Anfield: ''I think there were two buses parked today, never mind one.''
But statistics indicate Mourinho is by no means overly cautious
Chelsea's three Premier League title-winning seasons under him ended with them scoring 72 goals in both 2004-05 and 2005-06 and 73 in 2014-15, while his Real Madrid side netted a remarkable 121 times when they won the Primera Division in 2011-12
:: So what can we expect from a United side led by Mourinho?
What Mourinho has proven to be time and again in his pursuit of success is a pragmatist
That may have led to his teams on various occasions producing football widely regarded as less than exciting
But any suggestion he is a manager who has not shaped crowd-pleasing, attacking sides - nor ever will - looks considerably wide of the mark
And if something fundamental to Mourinho's management is sensible decision-making, surely he will take into account what seems clear from the case of Van Gaal - that failure to deliver attractive football at United is ultimately not tolerated
While there is every expectation United will be an organised outfit under Mourinho, there are plenty of reasons to believe they will be also be a dynamic one
Or, at least, a great deal more dynamic than Van Gaal's side
Source : PA
Source: PA