The 49-year-old has been handed a 12-month rolling contract - with the option of a further year or a return to his previous role as academy manager.
He becomes Leeds' third full-time boss this season after owner Massimo Cellino decided to dismiss Dave Hockaday and Darko Milanic.
Cellino today said in The Sun that Redfearn told him after the sacking of Hockaday that he was not ready to take charge.
He said: "Redfearn did not feel he was ready at that point.
"Then after I appointed Milanic, he came to me and said he was ready!"
Redfearn, however, appears excited for the challenge at the club he has supported since the age of six.
He said: "I've supported Leeds since a kid, I've worked for them for six years and I know this club like the back of my hand.
"It's certainly not a case of being frightened of it. As far as I am concerned, it's the right time for me and the right time for the club."