The 25-year-old defender has signed a four-year contract and is Malky Mackay's second signing of the summer following the arrival of striker Andreas Cornelius
|7/4||Cardiff are 7/4 with bet365 to be relegated
Brayford, who made 43 appearances in all competitions for Derby last season, says he is excited by moving to a Premier League club and is eagerly awaiting the challenge of playing in the top flight.
"When I heard Cardiff were interested in signing me then I was obviously very interested, especially at the prospect of playing in the Premier League and testing myself at the highest level," Brayford told the club's official website.
"Derby will always be a special club to me, but this was an opportunity I couldn't ignore."