The 22-year-old signed a three-and-a-half-year contract on Wednesday afternoon which will keep him at the Stadium of Light until 2016.
The Wearside club have paid a fee believed to be in the region of £3.8 million for the Frenchman, who moved to Turkish side Bursaspor from Nancy for £2.4m in 2011.
|WEDNESDAY TRANSFER ROUND-UP
|13/2||Sunderland are 13/2 with William Hill to beat West Ham 1-0 this weekend
N’Diaye, who is capable of playing at centre-back as well as in midfield, scored eight goals in 66 appearances for the Green Crocodiles.
Sunderland manager Martin O’Neill is delighted to have added the tough-tackling, hard-working, physical midfielder to his struggling squad.
“Alfred is a strong, powerful young player and as such can offer us more strength in depth,” the Black Cats boss told the club’s official website.
“He will give us options and I’m delighted that we have been able to bring him to the club.”
N’Diaye will wear the number four shirt for Sunderland, and could be involved in Saturday’s Premier League match against West Ham.