Radford has signed a two-year deal and will replace Daryl Powell when he joins Warrington Wolves at the end of this season.
The 42-year-old played for Hull and Bradford Bulls before joining the backroom staff at his home city club in 2011.
He became Hull’s head coach two years later, guiding them to Wembley success in 2016 and again the following year.
He was sacked in March last year and had been set to switch to rugby union as defence coach of American club Dallas Jackals.
Radford’s appointment was announced by Tigers this morning (Tuesday) and he said: “I’m really excited for the opportunity with a fantastic club and I’m really looking forward to taking up the challenge.
“I like what the club is about; from the outside it is a hard-working, honest, hard-faced club and I think you know what you’re getting when you come here.
“I think all those descriptions suit me down to the ground.”
Radford has big shoes to fill, but insisted: “I’m very aware of the brand of rugby that is played at this ground and it’s one I’m looking forward to having an effect on as well.
“How they play the brand of rugby they play here, I’ve always enjoyed watching it from the outside and I’ve always enjoyed coming up against it and trying to stop it.
“The job Daryl has done has been great over the years, as a club they have been in that tier of the best of the rest behind Wigan and Saints and ultimately trying to break that ceiling is going to be what the challenge is.
“I wouldn’t be coming here if I didn’t have aspirations to break that ceiling of what is the top couple of sides in the competition at the moment.
“That is something we will be working tirelessly as a club and as a group to achieve.”
Covid-19 restrictions could be lifted by the time Radford takes charge of his first game as Tigers boss and he admitted he’s relishing being home coach at the Jungle.
“The fact it is so enclosed and your spectators are on top of you, I say it all the time, it’s an unbelievable place to play and an unbelievable place to come and coach.
“To come and coach for the home team is something I am really looking forward to.”
Castleford chairman Ian Fulton is “thrilled” by Radford’s appointment and said the process of building next year’s squad has begun.
“Appointing our next head coach has been an incredibly extensive process, with applicants from both codes of rugby applying for the position and we as a board of directors are delighted to have secured Lee’s services,” he stated.
“He has already begun his work at identifying players for both retention and recruitment in 2022.”
But Fulton stressed: “Everyone at Castleford remains focused on the current task at hand in 2021 with our first team squad and head coach Daryl Powell, who we would love to see end his time with the Tigers on a deserved high note.”