Hock, 29, had been close to a move to the NRL with Parramatta in November, but will now join up with the Vikings, who announced his capture at their media day this morning.
An undisclosed fee has been paid for Hock’s services, although he will not be allowed to play against the Warriors this season, Wigan chairman Ian Lenagan confirmed.
Widnes are also hopeful that the deal could be extended beyond this year.
Last season was his first full season back in a Wigan shirt after serving a two-year ban for testing positive for cocaine in 2009.
He has made 148 appearances for the Warriors since coming through their academy system, and is contracted at the DW Stadium until the end of 2015.