The versatile Dutch centre-back underwent a medical and officially completed his £40million move from relegated Bournemouth to the Etihad on Wednesday evening, with Chelsea opting not to exercise a buy-back clause they inserted into the deal upon his initial switch from Stamford Bridge to the south coast in 2017.
Ake is the second new arrival in as many days at City, who also swooped to sign highly-rated young Spanish winger Ferran Torres from Valencia on Tuesday.
Guardiola had made new defensive recruits a priority after his side relinquished their Premier League title in 2019/20, finishing 18 points behind new champions Liverpool.
City fans hope that Ake will help fill the void left by Vincent Kompany's departure last summer, with further centre-back signings possible amid doubts surrounding the respective futures of both John Stones and Nicolas Otamendi.
The 25-year-old was a popular figure at Bournemouth - where he made 121 appearances across all competitions - and is relishing the opportunity to further thrive under Guardiola.
Ake told City's official website: “City have been the best side in England over the course of the last decade.
“Coming here is a dream for me. This is a top side full of world-class players. Everywhere you look in this squad there are big names with international pedigree.
“Pep is a manager admired across the world – what he’s done in the game speaks for itself. The success he’s had is unbelievable and the style of football he plays really appeals to me.
“I know I’m going to have to work hard to get into the side, but that’s what I’m here to do. I’ll do whatever I can to make an impact and help the team win silverware.”
City director of football Txiki Begiristain was effusive in his praise of Ake's individual qualities that he believes will make him a perfect fit for Guardiola's style of play.
“Nathan is a quality defender. He was a leader during his time at Bournemouth, and I am so pleased we’ve managed to bring him here," he said.
“He’s strong and quick, and we feel he has the technical and intellectual attributes needed to excel in Pep’s setup.
“Working with this squad, which is full of world-class players, will raise his level, and we are looking forward to seeing what he can achieve here in the coming years.”