Chairman Peter Ridsdale said: "The contract extension is great news for everyone connected to Cardiff City as Joe is one of the fantastic local talents that has emerged through the Academy system at the club.
"The club is proud to have local players of calibre among the first-team regulars, with Joe Ledley, Chris Gunter, Aaron Ramsey and Matt Smith all heavily involved with our experienced pros on a daily basis.
"We're very pleased that Joe wanted to commit himself to us by signing a new contract and look forward to his continued involvement and development in the future."