On 5 August 2021, Manchester City announced that they had signed Grealish on a six-year contract that would run until 2027.

It was reported by numerous outlets that the transfer fee paid to Aston Villa was for the amount of £100 million, which constituted the most expensive transfer of an English player ever, as well as the highest fee ever paid by a British club. Grealish was given the number 10 shirt by the team which had previously been worn by club legend Sergio Agüero, who departed from City the month prior after ten seasons with the team.