Wickham's current deal expires in the summer and there were worries that he could depart the Stadium of Light on a free, as result.
Gus Poyet has been trying to convince Wickham to extend his stay with the Wearsiders since the summer, but it has been a lengthy process.
Speculation had risen over the striker's future, with Leicester City and Newcastle United said to be interested, but his reported committal to stay should end these links.
Sunderland will now turn their attentions to tying down Lee Cattermole to a long-term contract.
The central-midfielder has been one of the club's star players this season, but his current deal expires in 2016 and they do not want to run the risk that they did with Wickham again.
Cattermole has earned a number of plaudits for the improvements that he has made since Poyet's arrival at the North East outfit and the tenacious 26-year-old is a crucial part of his plans at the club.
The side now plan to reward this good form by offering him improved terms, which they hope will keep Cattermole at Sunderland for the foreseeable future.