The 28-year-old, who can fill the majority of positions, has been one of the Wildcats' stand-out performers this season, scoring seven tries in eight games so far.
He was initially awarded a one-year deal in the off-season, but has now been rewarded for his form and will remain at the Rapid Solicitors Stadium until the end of 2014 as a result.
"When I signed, coach Rich Agar said that if I started well he'd look after me and we'd sit down and look at extending my stay," said Cockayne.
"I'm really happy to sign the extension. It's been great so far and it was all about me having another chance to play in Super League again. I'm really enjoying being at the club."
Wakefield are Cockayne's second Super League club, having initially made his name with Hull KR.
He joined the Robins from Doncaster in 2005 and won promotion to the top flight with them in 2006, going on to make over 100 appearances for the club.
He remains a cult hero with the Rovers fans, but left the club last summer owing to a disciplinary matter.
Cockayne spent the second half of the 2011 season with Championship side Featherstone, helping them win the Grand Final, before signing for Wakefield.