The Clarets have handed the out-of-contract Irishman a free transfer following nine years at Turf Moor, during which time he progressed through the youth ranks and went on to make 269 appearances.
Boss Sean Dyche last week revealed McCann, 25, has shunned the opportunity to discuss staying for a testimonial season. It comes among reported interest from the likes of Norwich and Celtic.
Upon the release of the club's retained list for next season, it was confirmed McCann has not been offered a new contract along with goalkeepers Brian Jensen - who has made over 300 appearances - and Jon Stewart as well as strikers Alex MacDonald and Wes Fletcher.
Out-of-contract first-choice keeper Lee Grant has already agreed a deal with Derby, which will be completed on July 1.
Youngsters Aryn Williams, Adam Evans, Joe Jackson and Shay McCartan have also seen their time at the Lancashire club come to an end.
However, fresh terms have been offered to striker Martin Paterson while fellow Northern Ireland international Michael Duff earns a 12-month extension.
Defender Jack Errington, who last year underwent heart surgery, has also had his deal extended, while striker Jason Gilchrist has earned his first professional contract.
Ex-Bristol City goalkeeper Tom Heaton has already agreed on a switch to Burnley and further new faces are set to be on their way.
