The 25-year-old England international has agreed a six-year deal after completing a move from Aston Villa.
Widely regarded as one of the best playmakers in the Premier League, Grealish is someone City fans will be familiar with, but here are 10 things you may not know about him…
Grealish, who has Irish grandparents and was eligible to play for the Republic of Ireland, played Gaelic Football in his youth.
In 2012, he scored a point for Warwickshire GAA at Croke Park – the home of the GAA – in an exhibition match at half-time during an All-Ireland quarter-final.
The midfielder was the inspiration behind a song from London-based rappers, The Manor, who released their aptly named ‘Grealish’ track ahead of EURO 2020.
Two of the group are Arsenal fans and felt compelled to pen a tribute the England international after a particularly impressive performance against the Gunners last season.
The lyrics include: Jack Grealish, king of the freemen, man of the match throw a party in the evening, and the man himself is said to be a big fan.
We need to talk about Kevin
In sealing his move to City, Grealish will get to link up with a player he has huge admiration for.
He went to school with former City defender Aoife Mannion, whom he played Gaelic football against.
Our new signing also played alongside a host of former players at Aston Villa, including Fabian Delph, Shay Given, Joleon Lescott and Micah Richards.
To date, Grealish has made 96 appearances in the Premier League, scoring 15 goals and providing 16 assists.
Grealish made his Aston Villa debut at the stadium he now calls home, coming on for the final two minutes as City won 4-0 on 7 May 2014.
Check out his first CityTV interview for his recollection of that day.
Keeping it in the family
The playmaker isn’t the only footballer in his family. His great-great-grandfather, Billy Garraty, won one cap for England and lifted the 1905 FA Cup with Villa.
The 25-year-old suffered penalty shootout heartbreak in the final of EURO 2020, but he has previously lifted silverware on the international stage.
In 2016, he helped England Under-21s win the Toulon Tournament, scoring twice in the competition.
Socks round the ankles and tiny shinpads have become something of a Grealish trademark since he established himself in the Premier League.
There have been plenty of stories as to why he wears them that way, but the midfielder set the record straight in his first interview with the Club.
"When I was 15, I was playing for the Under-18s and that year we were sponsored by Macron and the socks kept shrinking.
"I wasn’t a first team player so you couldn’t ask for new socks every day so I kept wearing them.
"They wouldn’t come over my calves within about two months into the season and that season I probably had my season where I took off and started kicking off. I started wearing them in games and thought I am going to keep this."
Everyone has them and for the playmaker it’s listening to the music of yesteryear, with Elvis and Queen two of his favourites.
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