Paolo Di Canio have allowed the pair leave after their contracts expired, while Danny Rose and Kader Mangane have returned to their parent clubs after loan spells
The pair will formally leave the club at the end of next month after the Paolo Di Canio opted to seek fresh talent, earlier suggesting the squad needs up to six new faces.
|10/1||Sunderland are 10/1 with Paddy Power to sign Richard Dunne
Kilgallon, meanwhile, never established himself with the Black Cats making only 23 appearances in his three years at the club, which included loan spells at Middlesbrough and Doncaster.
Di Canio also loses Danny Rose and Kader Mangane, who return to Tottenham and Al Hilal respectively after their year-long loan spells.
Ahmed Elmohamady and Ji Dong-won are set to return to Wearside after temporary spells at Hull and Augsburg.