The 24-year-old Wolfsburg man arrived in Manchester on Saturday and successfully underwent a medical before putting pen to paper on a long-term deal to join City.
“I want to reach the highest level possible as a player and I think the most important thing is that at the end of the season we can be happy and maybe have some titles,” De Bruyne told the club’s official website.
“I think this is the most important for the Club, the players and for the fans of course.
He becomes manager Manuel Pellegrini’s eighth signing of the summer transfer window following the arrivals of Raheem Sterling, Fabian Delph, Nicolas Otamendi, Patrick Roberts, Enes Unal, David Faupala and Aleix Garcia at the Etihad Stadium.
“We are very happy to have added Kevin to our team and I have no doubt that he will be a big success on his return to the Premier League,” Pellegrini said.
“It takes a special footballer to improve our squad and I have no doubt that Kevin is certainly one of those – he has all of the mental, physical, tactical and technical attributes required to fit straight in.
“We like to play attractive, attacking football and bringing in a player like De Bruyne will only aid us as we fight on four fronts.”
De Bruyne began his career at Genk in his home country before completing a £6.7m move to Chelsea in January 2012.
However, he endured an unsuccessful first spell in England, making just three appearances in the Premier League for Chelsea following a loan spell back at his former club.
De Bruyne spent the 2012-13 season on loan at Werder Bremen and took the Bundesliga by storm last season after making an £18m move from Chelsea to Wolfsburg in January 2014.
He scored 20 in 60 appearances during his 18-month spell at the Volkswagen Arena.