Manchester United are the winners of the 2016 Community Shield after beating Leicester City 2-1 at Wembley.
Ibrahimovic leapt above Leicester captain Wes Morgan in the 83rd minute to head Antonio Valencia's cross beyond Kasper Schmeichel, marking his official debut with a decisive contribution.
Jamie Vardy had earlier equalised after capitalising on a hideous lapse from Marouane Fellaini following Jesse Lingard's superb solo opener in the 31st minute.
United, who confirmed in an official statement before the match that Juventus have given midfielder Paul Pogba permission to have a medical with the club, started brightly, with Wayne Rooney and Ibrahimovic forming a lively forward pairing.
Another new signing, Eric Bailly, made an encouraging start, although he was regularly tested by Vardy, who displayed the same tenacity and directness that characterised his excellent performances last term.
Leicester threatened on the break, and Vardy's fine interplay with Shinji Okazaki resulted in the latter sending a lofted shot just wide of David De Gea's goal in the 18th minute.
Okazaki was denied by the crossbar a minute later when he met Marc Albrighton's corner with a powerful header as the champions served a warning of their offensive threat.
However, it was Lingard who opened the scoring after the half-hour mark.
The forward, whose sublime volley settled the FA Cup final against Crystal Palace in May, picked the ball up inside the Leicester half and slalomed past a quartet of attempted blocks before firing a low shot beyond Schmeichel.
The pace and movement of Leicester's half-time substitute Ahmed Musa unsettled United and Vardy equalised soon after the break, latching on to a blind backpass from Fellaini before rounding De Gea and finishing emphatically into an empty net in the 52nd minute.
Schmeichel was forced out of his area to snuff out a pair of United attacks as Mourinho's side pushed for a winner, while Musa missed the chance to become an instant hero at his new club when he sent an effort onto the roof of the net.
Ultimately, it was Ibrahimovic who made the difference. Having vowed to win a trophy in his first match with United, he duly did so by rising to meet Valencia's cross and deliver the first silverwear of the Mourinho era.