The 53-year-old Portuguese replaces Dutchman Louis van Gaal whose two-year reign at Old Trafford ended on Monday when he was sacked two days after United won the FA Cup.
"Jose is quite simply the best manager in the game today. He has won trophies and inspired players in countries across Europe and, of course, he knows the Premier League very well, having won three titles here," United executive vice-chairman Ed Woodward said in a statement.
"I'd like to take this opportunity to welcome him to Manchester United. His track record of success is ideal to take the club forward."
Mourinho, sacked by Chelsea in December, had been widely expected to succeed Van Gaal and his agent Jorge Mendes met United officials on Tuesday to discuss personal terms.
The talks with the former Porto, Inter Milan and Real Madrid manager became protracted, however, when it emerged that Chelsea, who sacked Mourinho in December, still owned his name as a trademark.
Now the stage is set for the marriage of two of world soccer's biggest names - Mourinho, the manager who collects trophies wherever he goes, and Manchester United, England's most successful club and a global giant.
"To become Manchester United manager is a special honour in the game," Mourinho said in the statement.
"It is a club known and admired throughout the world. There is a mystique and a romance about it which no other club can match.
"I have always felt an affinity with Old Trafford; it has hosted some important memories for me in my career and I have always enjoyed a rapport with the United fans.
"I'm looking forward to being their manager and enjoying their magnificent support in the coming years."
In two spells at Chelsea, the Portuguese won the Premier League three times - including their first league title for 50 years - and both the FA Cup and League Cup.
He also won league championships in his first seasons at Porto and Inter Milan before helping Real Madrid to their first La Liga crown in four years.
By their own high standards, United have struggled since Alex Ferguson retired three years ago, never finishing higher than fourth in the English standings.
Their fifth-place finish under Van Gaal this season meant they failed to qualify for the Champions League for the second time since Ferguson left.
Van Gaal did win the FA Cup - the first time United had lifted the trophy in 12 years - but due to widespread condemnation of the style of football his team played it was not enough to save him.
There are reservations about Mourinho's preferred style of play, with former United striker Eric Cantona saying the club should have opted instead for Pep Guardiola, who is taking over as manager of Manchester City.
But other former players, including goalkeeper Peter Schmeichel and former captain Steve Bruce, believe he will revive the club's fortunes.
Mourinho, who has won the Champions League with Porto and Inter Milan, will lead United in the Europa League next season.
Từ vựng liên quan
Tin tức liên quan

Former HCMC cop receives death for dealing drugs
news | 17326666A former major of the HCMC police department was sentenced to death in north-central Nghe An Province on Friday for trading over 22 kg of drugs.

Railway shutdown looms as staff salary entangled in red tape
industries | 327026600Trains might have to stop running from next month since over 11,300 railroad workers have not been paid their salaries due to bureaucratic wrangling.

Helicopter crashes in southern Vietnam during training session
news | 323586608A search and rescue mission is under way for the two pilot trainees and their teacher.

24 Chinese illegal entrants quarantined in Da Nang
news | 32767659724 Chinese nationals who entered Vietnam illegally to buy seafood have been caught and quarantined under the Covid-19 protocol by authorities in Da Nang City.

Samsung confirms launch of refurbished Galaxy Note 7s
business | 317306606The price for one starts at $611.

Vietnam braces for first tropical storm of 2019
news | 331076603A tropical depression in the Truong Sa Archipelago has gained strength and become Vietnam’s first storm of 2019.

Vietnamese consumer group eats humble pie for spreading fish sauce scare
news | 337206607Authorities have yet to punish the group even after condemning it for 'causing damage to fish sauce producers.'

Five of Euro 2016's biggest flops
sports | 329436602Ibrahimovic, Muller, Hart, Ramos, Turan are five stars who failed to live up to expectations.

Vietnam’s top tourist hotspots become deserted amid new coronavirus epidemic
places | 252446601Many popular tourist destinations, which are always favorite destinations of Chinese tourists, were not crowded as usual amid fears for the nCoV outbreak.