The 33-year-old defender marked his 100th senior cap for the Republic of Ireland with a stoppage-time equaliser to snatch a Euro 2016 qualifying draw with world champions Germany in Gelsenkirchen on Tuesday, and he has committed his future to the Black Cats on his return.
A delighted O'Shea said: "Since I arrived at Sunderland, I have enjoyed every minute and I'm really happy that I can continue here for another two years.
"To captain a club like this and to play in front of our fantastic supporters is a huge honour and I look forward to showing my commitment to the club on the pitch in the years to come."
O'Shea joined Sunderland during the summer of 2011 and has been a fixture in the team under successive managers.
Current head coach Gus Poyet is an unashamed admirer and was thrilled to have retained the services of one of his most dependable performers.
Power said: "I am delighted that John has agreed to stay with us for at least another two years
He is our captain, one of our leaders and I am sure he will continue to help us get better and stronger as a team.
"I really look forward to continuing to work with John."
O'Shea became just the sixth man to complete a century of caps for Ireland, and his goal was his third in a green shirt.
Source : PA
Source: PA