The former Manchester City manager Roberto Mancini has signed a three-year deal with Galatasaray.
The Turkish club sacked Fatih Terim last week.
Galatasaray added that the Italian will be paid $5.5 million for the rest of this season and just over $7 million for each of the following two seasons, excluding bonuses.
Mancini was dismissed as City manager in May after a three and a half year reign at the Etihad Stadium which included a Premier League title in 2012 and an FA Cup success a year earlier.
Terim, who is also the Turkey manager, was voted out of the Galatasaray job at a meeting of the club's board of directors after rejecting a contract extension.
Galatasaray, who in January spent heavily on Didier Drogba and Wesley Sneijder, have made a disappointing start to the season, and are 10th in the Turkish League.
They have taken seven points from five league games and were thrashed 6-1 at home by Real Madrid in the Champions League.