Benjamin Mendy becomes the third full back to join Pep Guardiola's side this summer, after the arrivals of Kyle Walker and Danilo. The deal takes City's total spending on full-backs to £133million.
The 23-year-old has penned a five-year deal with the club and will wear the No 22 shirt at the Etihad Stadium.
Speaking to the club's website, Mendy said: 'I am absolutely delighted to be joining Manchester City. They are one of Europe's leading clubs and in Pep Guardiola they have a manager committed to playing attacking football. I am sure that over the next few years we will be successful.'
City's Director of Football, Txiki Begiristain, added: 'Benjamin has all the qualities we are looking for in a full-back. For such a young player, he has a wealth of top-level experience.'
'He is undoubtedly one of the world's best full-backs, our number one target in this position. We are all delighted to have him here at Manchester City. I'm sure he will prove a fantastic addition to the squad.'
Mendy will now join up with his new-team mates on City's pre-season tour of America.
.@benmendy23 is a!
— Manchester City (@ManCity) July 24, 2017
Check out the signing gallery for his first shots in #mcfc colours!
https://t.co/zu0fuCuf4b #BlueMendy pic.twitter.com/Vks2OybQ7t
Proud to announce you guys that I've officially joined @ManCity today !! A dream come true to play under Pep's orders #BM22 pic.twitter.com/3X18oIzDmC
— Benjamin Mendy (@benmendy23) July 24, 2017