Leuluai has signed a deal which will see him playing for the next few years and then taking up an Assistant Coach role once his playing days are over.
31-year-old Leuluai re-joins Wigan for the 2017 season after four years with NRL side New Zealand Warriors.
Wigan Warriors Chairman, Ian Lenagan, said: “It was always part of our long term plans for Tommy to return to Wigan. We have remained in contact over the last few years and it is clear that he still has a great affinity for the Wigan Club.
“Tommy was invited back to Wigan during last year to help him rehabilitate after injury and to contribute to the coaching and team spirit of the players.
“He was always a natural leader on and off the pitch previously but his time in New Zealand and the NRL has improved these qualities even further. We believe his maturity, leadership, positional flexibility and strength will make him an excellent addition to the Wigan squad.
“It is clear also that Tommy has all the attributes needed to become a very good coach and we look forward to him starting that stage of his career with us in a few years’ time.
Thomas Leuluai said: “With my wife being from Wigan and us having a new-born baby, I thought for my family it would be better for us to be back in England.
“I had a bit of a look around in Super League but, as soon as I knew that Wigan were interested, it was a no-brainer to be honest. I’ve got a lot of close friends at Wigan and I really love the Club and its history.
“I really enjoyed my time there and I look forward to coming back and representing the Club with the pride and the passion that it deserves and to winning some more trophies before moving on to a career in coaching.”
Wigan Warriors Head Coach, Shaun Wane, said: “Tommy is a fantastic player that needs little introduction to the Wigan fans. Hard-hitting, tough and uncompromising, he is a player that really leads from the front.
“He is very experienced and a great addition to the playing squad for the next few years. His very presence just improves us and we are confident that Tommy will also enjoy a successful coaching career after he has finished playing.”