Hodgson, 39, who made 102 appearances for the Tigers from 2004 to 08 and was in their 2005 Premiership-winning team, has been appointed as assistant to Wests head coach Ivan Cleary.
Hodgson said: "I would like to thank everyone at Widnes Vikings. I have enjoyed my time here and will leave with some special memories.
"Widnes Vikings gave me a great opportunity to coach and I will always be grateful for everything that I have learned here. I am excited to take the next step in my career with Wests Tigers, which offers a fantastic opportunity to return to a club that I know well and develop my career in the NRL.
"I'm extremely happy to be returning to Wests Tigers; the memories have been flooding back to me and I'm looking forward to getting started."
Hodgson was named Man of Steel in 2009 after helping Huddersfield Giants reach Wembley in his first season and also enjoyed three successful years with Warrington Wolves before hanging up his boots and joining the backroom staff of the Vikings.
Widnes chief executive James Rule said: "It was an easy decision for Denis (Betts) and I to give Brett his first full-time coaching role, as we could see the potential that he had.
"He has fulfilled that potential, not only in working with the senior players but also in his excellent work with our academy."