The new deal will keep the 23-year-old at Derby until the summer of 2014. Brayford was named Derby fans’ player of the year last season.
“This is fantastic news for Derby County and we’re delighted to announce John has extended his contract,” Derby manager Nigel Clough told the club’s official website.
“He is a joy to work with and it is significant for this club that someone with his potential and consistency of performance has committed his long-term future here.
“We’re almost at the stage now where John’s good performances go uncommented on because they are delivered in a typically understated, professional and dedicated way.”