After recently being closely linked with the Senegalese centre-half, the Black Cats have finalised a deal for the 29-year-old on a short-term basis from Al-Hilal
The defender arrived in the North East yesterday, and after productive talks has been confirmed as the Black Cats' second acquisition of the January transfer window, after Alfred N'Diaye joined from Bursaspor last week.
Mangane is currently part-way through a three year contract with Saudi Arabian side Al-Hilal, and the deal means that the Senegalese international will stay at the Stadium of Light on loan until the end of the season, with a view to a permanent move in the summer.
"Kader is a player who will add to the overall strength of our squad and give us options," Sunderland boss Martin O'Neill told reporters.
"He will improve competition for places and we are delighted to welcome him to the club."
Mangane, linked with both Arsenal and West Ham last summer, made over 100 appearances for Rennes between 2008 and 2012, and has made six appearances for the Senegalese international side, scoring once.