The 26-year-old joined the Black Cats on a four-year deal for an undisclosed fee.
The transfer comes seven years after Kaboul’s agent stated that his client “wouldn’t join Sunderland even if there was an earthquake”.
Kaboul had been linked with a move to Galatasaray by the Turkish newspaper Fanatik. The report claimed that Kaboul is Galatasaray manager Hamza Hamzaoglu’s primary target this summer.
The Istanbul giants set aside €3.5 million for the France international’s transfer fee and wanted to wrap up the deal by the end of the week.
Galatasaray have also expressed an interest in Tottenham centre back Vlad Chiriches.
The experienced defender fell out of favour with head coach Mauricio Pochettino last season and struggled for playing time only making 15 appearances all season. Kaboul defender still has another season left on his contract.