It will be the third time that Duffy, 29, has been at the club after two previous spells between 2001 and 2005, during which he helped the club lift the National League One Grand Final.
Leigh’s Head Coach, Ian Millward, said: “I know a lot of people that know John.
“As a person and as a player they speak very highly of him. I look upon him as a very multi-skilled player who can play hooker and in the halves.
“He’s a player that can create a lot of doubt with the ball in his hands and I just seem to think with his experience and versatility, that he’s a really good buy for the club. He knows the competitions very well and is probably one of the best players in the division.”
Duffy also had a spell at Whitehaven before switching to the Vikings but admits that Leigh is where his heart lies.
“I didn’t really want to leave Leigh in the first place. I had to look after my family and was gutted to leave. I’m now glad to be back and can’t wait for the challenge ahead,” he said.
“I’m really excited. Since I’ve been away from Leigh, I’ve gained a lot of experience with new challenges and I think that I’ve come on as a player in leaps and bounds. As I’ve got that bit older I’ve done my bit to help younger players coming through and hopefully I can help at Leigh.
“I’d like to thank Allan, Arthur and Paul for helping me to come back and I’m keen to work with Ian Millward and show everyone what I can do.”