City said the cardigan was bagged at a charity auction by American fan James Hodge for £6,000 ($11,000), which would go towards providing free meals to families in Manchester during the school holidays.
"I'm delighted that this auction has raised so much for City in the community and thank you to everyone who has donated for such a great cause," Guardiola told the club's website.
"It's also fantastic to be able to give something personal to the fans whose support helped us achieve incredible success last season."
Guardiola's side became the first team to claim the English treble of the league championship as well as the League Cup and FA Cup last season.
City will kick off their 2019-20 Premier League season with an away trip to West Ham United on 10 Aug.