The 23-year-old collected the sport’s most coveted individual honour from Olympic gold medallist and Tour de France winner Bradley Wiggins at a gala presentation dinner at The Point, Manchester.
Tomkins, a two-time winner of the Super League Young Player of the Year award and 2011 Man of Steel nominee, has been in outstanding form for a Wigan team which ended the 2012 regular season as Super League leaders.
He secured the award, which is decided by a secret ballot of every Super League player, ahead of St Helens hooker James Roby and Ben Westwood, the Warrington Wolves second row.
Wigan Warriors were also named 2012 Super League Club of the Year.
Super League Grand Finalists Leeds Rhinos collected three awards at the Man of Steel dinner, the highlight Zak Hardaker being named Young Player of the Year.
Hardaker, 21, played in every round of Super League in 2012 as well as the Challenge Cup final at Wembley and is expected to start at full-back at Old Trafford on Saturday.
He pipped Josh Jones of St Helens and Bradford Bulls second row John Bateman to the award.
A momentous year in the history of Bradford Bulls was acknowledged by Mick Potter being named Super League Coach of the Year. Potter, who coached the Bulls on an unpaid basis for two months after the club went into administration, was selected by a secret ballot of all 14 Super League coaches.
Leeds prop Jamie Peacock was the winner of the Mike Gregory Spirit of Rugby League Award, an award made to an individual who is acknowledged as having lived the values of the sport over an extended period of time. It is named in honour of the late Mike Gregory, the former Warrington and Great Britain player.
Danny McGuire of Leeds Rhinos was crowned 2012 Community Champion for his unselfish work on behalf of Mencap, a charity he has supported tirelessly throughout 2012.
Three retiring Super League players, Ben Jeffries (Wakefield Trinity, Bradford Bulls), Danny Orr (Castleford Tigers, Wigan Warriors, Harlequins) and Ryan Hudson (Castleford Tigers, Huddersfield Giants, Wakefield Trinity) were presented with Outstanding Contribution Awards to mark their long service to the competition.
The award winners in full from the 2012 Stobart Super League Man of Steel dinner are as follows:
Top metre maker – James Roby (St Helens) with 3,971 metres
Top try-scorer – Josh Charnley (Wigan Warriors) with 31 tries
Hit man – Danny Washbrook (Wakefield Trinity Wildcats) with 991 tackles.
Lifetime Achievement – Danny Orr (Castleford Tigers, Wigan Warriors, Harlequins), Ryan Hudson (Castleford Tigers, Huddersfield Giants, Wakefield Trinity), Ben Jeffries (Wakefield Trinity Wildcats, Bradford Bulls),
Carnegie Community Champion – Danny McGuire (Leeds Rhinos)
Club of the Year – Wigan Warriors
Mike Gregory Spirit of Rugby League – Jamie Peacock MBE (Leeds Rhinos)
Young Player of the Year – Zak Hardaker (Leeds Rhinos)
Coach of the Year – Mick Potter (Bradford Bulls)
Man of Steel – Sam Tomkins (Wigan Warriors)