Ibrahimovic made his debut for hometown club Malmo in 1999 and went on to play for Ajax, Juventus, Inter Milan, Barcelona and AC Milan before joining PSG.
He has scored 392 goals in 677 games and last season was his most prolific, with 50 goals in 51 matches – a record for the French club. His tally of 38 league goals was also a club record.
The player – who retired from international football after Sweden’s exit from Euro 2016 earlier this month – has won a trophy every season of his career since 2001, including 13 league titles.
In his four seasons at PSG, Ibrahimovic won 12 trophies, including the domestic quadruple twice.
What former players say
Best of friends
Ibrahimovic had earlier said he had “many options” for next season, including a return to Italy – but the lure of working with Mourinho has proved too strong.
He played under the 53-year-old Portuguese at Inter in 2008-09, helping them win the Serie A title, before joining Barcelona.
In his book I Am Zlatan Ibrahimovic, he described Mourinho as a manager he was “willing to die for”.
Speaking recently on Mourinho’s appointment at United, he said: “He is the man to bring them back to the top. I had a fantastic time working with him. If we will work again I don’t know.”
Worst of enemies
However, Ibrahimovic is not so complimentary of the new Manchester City boss Pep Guardiola, whom he played under for two seasons at Barcelona.
He referred to the Spaniard as a “spineless coward” in his autobiography, and Barcelona president Josep Maria Bartomeu revealed Ibrahimovic said he “might punch Pep” during his time at the Nou Camp.
Football finance expert Rob Wilson, of Sheffield Hallam University, says Ibrahimovic would be United’s most marketable player since Cristiano Ronaldo, with shirt sales alone topping £50m – enough to cover the cost of failing to qualify for this season’s Champions League.
“Zlatan has a global profile and global appeal,” Wilson said. “Fans will buy shirts with Ibrahimovic on the back in Africa, South East Asia – markets United had a foothold in but not the leverage.
“Only a few select few players can do that: Gareth Bale, Neymar, Lionel Messi and Ronaldo.”
The ego has landed
Ibrahimovic has an ego to match his footballing talents and is renowned for some outrageous statements, which might – or might not – be tongue in cheek.
When Arsene Wenger wanted the then teenage Ibrahimovic to have a trial for Arsenal in 2000, he instead chose to join Ajax saying: “Zlatan doesn’t do auditions.”
On another occasion, after Sweden missed out on the World Cup finals in Brazil in 2014, he said: “One thing is for sure, a World Cup without me is nothing to watch.”
BBC Sport’s Simon Stone
The imminent arrival of Ibrahimovic looks to be perfect for Manchester United.
Their history is littered with temperamental big-name players: George Best, Eric Cantona and Cristiano Ronaldo to name but three.
The big question is whether, at 34, the striker can adapt to the physical demands of the Premier League.
Delve into the past of this contradictory forward and it seems he is at his best when questions are at their fiercest.
But, as every stockbroker will tell you, past performance is no guarantee of what will happen in the future.