In a short post on Twitter, the club wrote: 'City are delighted to announce the signing of Brazilian midfielder Douglas Luiz #WelcomeDouglas'.
He is the second Brazilian to join Manchester City in less than a year after the arrival of striker Gabriel Jesus from Palmeiras in January.
However, it's understood that he will be loaned out to Spanish side Girona for the 2017-18 season, although neither club has confirmed that move, and City say they will make a statement on his future "in the coming days".
Duminy dropped for second Test
By the close of play, he had an unbeaten 184 to his name and England had a grip on a game they eventually won inside four days. Joe Root was dropped twice and he made South Africa pay by scoring a mammoth 190 at Lord's.
Former JC Iftikhar Chaudhry asks Nawaz to step down
Those who call themselves leaders have no say in the public while Muhammad Nawaz Sharif is a leader of global stature, he added. He said when former President Pervez Musharraf ousted Nawaz Sharif then Nawaz Sharif tried twice to return to country.
Funeral for whale rescuer Joe Howlett underway
As well, the government has imposed a partial closure within a nearby snow crab fishing area that whales are known to frequent. Currently, there are only about 500 North Atlantic right whales left on the planet and seven were found dead in the Gulf of St.