The 24-year-old fullback will move to New Zealand later in the year after Englands 2013 Rugby League World Cup campaign to take up a three-year contract with the Mount Smart Stadium club.
Tomkins will give the Vodafone Warriors arguably the most exceptional try-scorer in the game today as they look forward to marking the clubs 20th season in 2014 since entering the NRL in 1995.
This year alone he has 34 tries in a total of 24 Super League and Challenge Cup matches including one in Wigans Challenge Cup final win at Wembley last month while his career tally runs at almost a try a game (144 in 150 games). He also has a try-a-game strike rate for England at Test level.
Confirming his signing overnight (NZ time), Tomkins said he was hugely excited about challenging himself in the NRL.
I still have business to take care of with Wigan but Im over the moon knowing Ill be with the Vodafone Warriors for the next three years, he said.
I was thrilled to meet up with (owner) Eric Watson and the club has been terrific throughout. They flew Mum out to New Zealand so they could show her around and she was absolutely blown away by what Auckland had to offer. I was in New Zealand with England for the Four Nations in 2010 and loved what I saw then.
For me this is about taking another step up in my career by testing myself in the NRL. It has always been a goal of mine and now its going to happen.
Im really grateful to Wigan for helping to make this possible by giving me an early release. I love the club and the people here and always will but this is the next big step for me.
The Vodafone Warriors secured Tomkins ahead of a number of other NRL clubs as well as rugby union clubs in France and the United Kingdom.
Owner Eric Watson hailed the signing as one of the most significant since he took over the Vodafone Warriors in late 2000.
Sam is unquestionably among the biggest names in the game today, certainly the biggest in England, he said.
Ive been so impressed in the dealings Ive had with him and I couldnt be more excited about seeing him play for the Vodafone Warriors. I have every confidence hes going to make his mark in the NRL.
Vodafone Warriors head coach Matthew Elliott said Tomkins arrival would provide a huge boost to the clubs 2014 NRL campaign.
Sams an exciting addition to our squad, a world-class player who supports the direction we want to go in with this club, he said.
Im certainly looking forward to working with him and seeing what he will bring to our team. Signing a player of this calibre is hugely significant for us.
Elliott pointed to the Burgess brothers at South Sydney as well as the Bulldogs James Graham as examples of players moving from the United Kingdom to make their mark in the competition. In recent times Adrian Morley and Gareth Ellis also impressed when they switched from the English Super League while the Vodafone Warriors recently announced they had signed 18-year-old Leeds forwards Jordan Baldwinson and Mason Tonks to join their NYC squad next season.
Vodafone Warriors chief executive Wayne Scurrah said the club deeply appreciated the role Wigan owner and chairman Ian Lenagan had played in making the signing possible.
We have enormous respect for Ian and Wigan for the way theyve handled this process, he said.
Theyve been fantastic in working with Sam to enable him to fulfil his desire to join the Vodafone Warriors and play in the NRL. Its a thrill for us being able to sign him, a huge day in our history.
Lenagan said Tomkins would leave Wigan with the clubs full support.
We have a principle of developing players to enable them to take up opportunities at the highest level, like playing in the NRL, he said.
We have the greatest admiration for the NRL and are fully aware of how highly the players regard it.
Were disappointed to see Sam going but we want to give him this opportunity. Sam knows that there will always be a place for him to one day return to his hometown club.
Tomkins signing also underlines the sister club relationship developed recently, which has included reciprocal visits. Wigan general manager Kris Radlinski spent time at the Vodafone Warriors recently while Vodafone Warriors assistant coach Ricky Henry visited Wigan in July. Scurrah and Vodafone Warriors general manager Football operations Dean Bell also visited Wigan earlier this season.
Scurrah said both clubs plan to combine on a number of initiatives in the future.
Born: March 23, 1989
Birthplace: Milton Keynes, Buckinghamshire, England
Junior Clubs: Chorley Panthers, Wigan St Patricks
Previous Clubs: Wigan Warriors 2008-2013
Debut: Wigan v Whitehaven, JJB Stadium, May 12, 2008 (Challenge Cup)
Career Games: 150 appearances 2008-2013
Career Points: 646 points (144 tries, 35 goals, 2 field goals)
Representative: 20 Tests for England 2009-2013 (21 tries)