The 50-year-old was replaced as the head coach by Uwe Rosler in May.
He was subsequently offered the chance to return to his previous role in charge of the club's academy but in a statement today (below) he announced that he has not taken up the option.
Redfearn guided the Whites to safety last season after taking over on a permanent basis in November.
Redfearn said in his statement: "It is with great sadness that I am resigning from my employment at Leeds United with immediate effect.
"I am desperately disappointed that Adam Pearson's 'offer' of a return to my old position as Academy manager was not genuine and the club have since made my position untenable by refusing to let me take up my post at Thorp Arch.
"I would, however, like to place on record my thanks to everyone connected with the first team, including the fans, for making last season both productive and beneficial after a difficult start.
"Very importantly I would like to pay a special tribute to the Academy where I proudly worked along with others for the best part of six years.
"The LUFC academy is now regarded as one of the most productive in the country and last season proved testament to that with the continued development of Sam Byram, Alex Mowatt, Lewis Cook, Charlie Taylor, Kalvin Phillips, Lewis Walters and Chris Dawson amongst a crop of outstanding young players to wear the Leeds badge of honour and to don the famous white shirt.
"The Academy Philosophy and Coaching programme that I wrote and developed will be part of my legacy to this great club and hopefully will help shape more top young professional footballers moving forward.
"I would like to wish Uwe Rosler and his staff and players every success for next season and beyond so that Leeds can (get) back to the Premier League very soon
"Last, but not least, I wish to thank the fans for their unstinting support both during my time at the Academy and whilst in charge of the first team.
"It has truly been an honour to represent and serve this great club."