The striker has signed a new four-and-a-half-year deal that will keep him at the Stadium of of Light until the summer of 2019.
Wickham joined Sunderland from Ipswich in 2011, and last season became a big figure in the side as they avoided relegation from the Premier League with the 21-year-old notably scoring important goals in away games against Chelsea and Manchester City.
So far, he has scored a total of 12 goals from 67 appearances but his form has picked up significantly under his current manager, having found the net on five occasions towards the end of the last campaign, and has struck three times this term.
The Sunderland boss told the club's website: “I’m delighted that Connor has committed his future to us for the next few years. After his contribution at the end of last year, he has continued to improve his football and become an important part of our team.
"He keeps learning, he is able to adapt to different positions up front and he is enjoying our philosophy of play so I’m really looking forward to keep working with him for the benefit of our club.
“I think it was very important to tie down a young English centre forward as there are not many around; this shows clearly the way this football club wants to progress.”