The 25-year-old is now the most expensive player in British footballing history at £100 million, the 25-year-old penning a six-year deal with the Premier League champions on Thursday.
Grealish's arrival makes Pep Guardiola's side an even more formidable entity going into the 2021/22 season.
The former Aston Villa man is now part of arguably the best attacking unit ever assembled in English football.
Grealish, Kevin De Bruyne, Riyad Mahrez, Raheem Sterling, Gabriel Jesus, Ferran Torres and Phil Foden in one squad? That should be illegal to be honest.
City fans will be eager for their new signing to hit the ground running and there's a very good chance that he will do just that.
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Grealish knows the Premier League inside out and he's also familiar with a number of City players thanks to his days on international duty with England.
That will come in very handy, although Grealish was guilty of slyly mocking one of his new club colleagues in the build-up to Euro 2020.
Video: Grealish mocks City in front of Foden
Grealish first asked Henderson: "You know when you won the Champions League, did you wear a suit for the final?"
After the Liverpool captain replied with a yes, 'Super Jack' added: "It must be annoying, you know when they change it up for a final and you get beat."
Foden certainly wasn't impressed...
Grealish and Henderson saw the funny side, though, and to be fair to City's new signing, he was bang on the money about his new club's struggles against Chelsea in the Champions League final.
Guardiola made a number of questionable tactical decisions for the game, including playing Ilkay Gundogan as the team's holding midfielder.
Chelsea won the match in Porto 1-0 thanks to a goal from Kai Havertz and it's a night City fans will be eager to forget.
The only way that will be possible is if the team triumph in the Champions League next season, which is something Grealish will be desperate to help achieve in order to live up to his enormous price tag.