Following the club’s promotion from League One, the likes of Aiden McGeady, Lee Burge and Jordan Willis all left Wearside following the end of their contracts, while Nathan Broadhead, Thorben Hoffmann and Callum Doyle returned to their parent clubs following loan spells.
Since then Sunderland have re-signed three players who were out of contract, while making ten more signings.
There have also been some loan departures from the Stadium of Light.
We take a look at every deal completed by Sunderland this summer:
1. RE-SIGNED: Lynden Gooch
There were offers from other Championship clubs, yet the 26-year-old elected to extend his ten-year stay at Sunderland by signing a new two-year deal. Photo: FRANK REID
2. RE-SIGNED: Patrick Roberts
Roberts only joined Sunderland on a short-term deal in January but also signed a new two-year contract after helping the club win promotion from League One. Photo: Martin Swinney
3. RE-SIGNED: Bailey Wright
It was a summer to remember for the Australian centre-back, who won promotion at Wembley, helped Australia qualify for the World Cup and then signed a new two-year contract at Sunderland. Photo: Frank Reid
4. IN: Leon Dajaku
A clause in the German's contract was triggered at the end of last season after Dajaku met the requirements to make his Sunderland move permanent. The 21-year-old has featured just once in the Championship so far this campaign and has been struggling with a groin issue. Photo: Ian Horrocks