The 25-year-old Netherlands international is our second signing of the summer, following in Ferran Torres footsteps and has agreed a five-year deal with the Club.
With 146 Premier League appearances to his name, Ake is someone City fans will be familiar with, but here are 10 things you may not know about him...
Ake started playing football as a four-year-old, when his older brother’s coach invited him to join in a training session because he had been turning up to watch each week.
He joined local amateur side VV Wilhelmus at the age of six, but was snapped up by professional outfit ADO Den Haag at 12.
Ake is a two-time winner of the U17 European Championships, having helped the Netherlands to back to back titles in 2011 and 2012.
He captained the side in the latter, scoring in the penalty shootout in the final and was named in the Team of the Tournament.
At Chelsea he lifted the FA Youth Cup in 2011-12 and captained the U21s to the 2013/14 U21 Premier League title.
Nathan’s brother Cedric is four years older than him and was a promising footballer himself.
He was signed by ADO Den Haag in his late teens but gave up the chance of a professional career to move to London in order to support his brother when he signed for Chelsea.
Ake has represented the Netherlands at every level from U15s, but was also eligible for the Ivory Coast through his father, Moise.
He won 68 youth caps for the Oranje and captained the U17s and U19s before making his senior debut in a 2-1 win over Morocco in May 2017.
At Bournemouth he was part of a dog walking club, which included winger Ryan Fraser and midfielder Dan Gosling. The trio would meet regularly to walk their dogs on the beach.
Tickling the ivories
He bought a piano to keep himself entertained in lockdown and was self-teaching via an app.
Ake has admitted he would stew over defeats or poor performances for a number of weeks as a young player.
He has since changed and the turning point was City’s last gasp 2-1 victory at Bournemouth at the start of the 2017/18 season.
The defender said he didn’t want leave the house for a week after the loss, but changed his mindset after a conversation with Eddie Howe.
Beginning his career as a defensive midfielder, Ake has also been utilised at left-back as well as centre-half.
As recently as 2016 he said his favoured position was at the base of midfield, before making the defensive position his own at Bournemouth.
Record to forget
He has never beaten City in his senior career, having lost all five of the games he has played against his new club.
Ake has won awards at each of the three previous clubs where he has played an entire season.
He was named Chelsea’s Young Player of the Year in 2013/14 and repeated the trick whilst on loan at Watford in 2015/16.
Bournemouth fans picked him as their Player of the Season in 2017/18.